HIV protease inhibitors, compositions containing the same, their pharmaceutical uses and materials for their synthesis

ABSTRACT

Compounds of the formula:  
                 
where the formula variables are as defined herein, are disclosed that advantageously inhibit or block the biological activity of the HIV protease. These compounds, as well as pharmaceutical compositions containing these compounds, are useful for treating patients or hosts infected with the HIV virus. Intermediates and synthetic methods for preparing such compounds are also described.

This application claims the benefit of U.S. Provisional Application No. 60/297,460, filed on Jun. 11, 2001, and U.S. Provisional Application No. 60/297,729, filed on Jun. 11, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to novel compounds as useful as HIV protease inhibitors and to the use of such compounds as antiviral agents for treatment of HIV infected individuals. This invention also relates to methods of preparation of these compounds and to intermediates that are useful in the preparation thereof.

2. Related Background Art

Acquired Immune Deficiency Syndrome (AIDS) causes a gradual breakdown of the body's immune system as well as progressive deterioration of the central and peripheral nervous systems. Since its initial recognition in the early 1980's, AIDS has spread rapidly and has now reached epidemic proportions within a relatively limited segment of the population. Intensive research has led to the discovery of the responsible agent, human T-lymphotropic retrovirus III (HTLV-III), now more commonly referred to as the human immunodeficiency virus or HIV.

HIV is a member of the class of viruses known as retroviruses. The retroviral genome is composed of RNA, which is converted to DNA by reverse transcription. This retroviral DNA is then stably integrated into a host cell's chromosome and, employing the replicative processes of the host cells, produces new retroviral particles and advances the infection to other cells. HIV appears to have a particular affinity for the human T-4 lymphocyte cell, which plays a vital role in the body's immune system. HIV infection of these white blood cells depletes this white cell population. Eventually, the immune system is rendered inoperative and ineffective against various opportunistic diseases such as, among others, pneumocystic carini pneumonia, Kaposi's sarcoma, and cancer of the lymph system.

Although the exact mechanism of the formation and working of the HIV virus is not understood, identification of the virus has led to some progress in controlling the disease. For example, the drug azidothymidine (AZT) has been found effective for inhibiting the reverse transcription of the retroviral genome of the HIV virus, thus giving a measure of control, though not a cure, for patients afflicted with AIDS. The search continues for drugs that can cure or at least provide an improved measure of control of the deadly HIV virus.

Retroviral replication routinely features post-translational processing of polyproteins. This processing is accomplished by virally encoded HIV protease enzyme. This yields mature polypeptides that will subsequently aid in the formation and function of infectious virus. If this molecular processing is stifled, then the normal production of HIV is terminated. Therefore, inhibitors of HIV protease may function as anti-HIV viral agents.

HIV protease is one of the translated products from the HIV structural protein pol gene. This retroviral protease specifically cleaves other structural polypeptides at discrete sites to release these newly activated structural proteins and enzymes, thereby rendering the virion replication-competent. As such, inhibition of the HIV protease by potent compounds may prevent proviral integration of infected T-lymphocytes during the early phase of the HIV-1 life cycle, as well as inhibit viral proteolytic processing during its late stage. Additionally, the protease inhibitors may have the advantages of being more readily available, longer lived in virus, and less toxic than currently available drugs, possibly due to their specificity for the retroviral protease.

Related inhibitors of HIV proteases have been described in, e.g., U.S. Pat. No. 5,962,640, U.S. Pat. No. 5,932,550, Australian Patent No. 705193, Canadian Patent Application No. 2,179,935, European Patent Application No. 0 751 145, and Japanese Patent Application No. 100867489. Other related HIV protease inhibitors have been described in K. Yoshimura, et al., Proct. Natl. Acad. Sci. USA, 96, 8675-8680 (1999) and T. Mimoto, et al., J. Med. Chem., 42, 1789-1802 (1999).

On-going treatment of HIV-infected individuals with compounds that inhibit HIV protease has led to the development of mutant viruses that possess protesases that are resistant to the inhibitory effect of these compounds. Thus, to be effective, new HIV protease inhibitors must be effective not only against wild-type strains of HIV, but must also demonstrate efficacy against the newly emerging mutant strains that are resistant to the commercially available protease inhibitors. Accordingly, there continues to be a need for new inhibitors targeting the HIV protease in both wild type and mutant strains of HIV.

SUMMARY OF THE INVENTION

This invention relates to compounds useful for inhibiting the activity of HIV-protease of Formula I:

wherein:

-   -   R¹ is a 5- or 6-membered mono-cyclic carbocyclic or heterocyclic         group, wherein said carbocyclic or heterocyclic group is         saturated, partially unsaturated or fully unsaturated and is         unsubstituted or substituted by one or more suitable         substituents;     -   R² is a substituted alkyl group, a substituted or unsubstituted         alkenyl group, a substituted or unsubstituted alkynyl group, a         substituted phenyl group, a substituted phenylalkyl group, a         substituted or unsubstituted phenylalkenyl group or a         substituted or unsubstituted phenylalkynyl group,     -   R^(2′) is H or a substituted or unsubstituted C₁-C₄ alkyl group;     -   X is     -    wherein R^(x) is H or one or more suitable substituents;     -   Z is S, O, SO, SO₂, CH₂ or CFH;     -   R³ is H or a substituted or unsubstituted C₁-C₄ alkyl group;     -   R⁴, R⁵, R⁶ and R⁷ are independently selected from H or a C₁-C₆         alkyl group; and     -   R⁸ and R^(8′) are independently selected from H, halo, a C₁-C₄         aliphatic group or a C₁-C₄ halo-substituted aliphatic group;     -   where any of said substituted alkyl, alkenyl or alkynyl groups         are substituted by one or more suitable substituents     -   provided that said 5- or 6-membered mono-cyclic         heterocycloalkyl, heterocycloalkenyl or heteroaryl group         contains at least two heteroatoms when R² is a substituted         phenyl group, a substituted phenylalkyl group, a substituted or         unsubstituted phenylalkenyl group or a substituted or         unsubstituted phenylalkynyl group; or     -   provided that said alkyl, alkenyl or alkynyl moiety of said         substituted phenylalkyl, phenylalkenyl or phenylalkynyl group is         substituted by one or more substituents selected from halo or         keto; or     -   provided that said substituted phenyl group or phenyl moiety of         said substituted phenylalkyl, phenylalkenyl or phenylalkynyl         group is substituted by one or more suitable substituents other         than halo or methyl.

The present invention relates to compounds of Formula I below, and prodrugs, pharmaceutically active metabolites, and pharmaceutically acceptable salts and solvates thereof that inhibit the protease encoded by human immunodeficiency virus (HIV) type 1 (HIV-1) or type 2 (HIV-2), as well as mutant strains thereof. These compounds are useful in the treatment of infection by HIV and the treatment of the acquired immune deficiency syndrome (AIDS). The compounds, their pharmaceutically acceptable salts, and the pharmaceutical compositions of the present invention can be used alone or in combination with other antivirals, immunomodulators, antibiotics or vaccines. Compounds of the present invention can also be converted to prodrugs, by derivatization, according to conventional techniques. Methods of treating AIDS, methods of treating HIV infection and methods of inhibiting HIV protease are disclosed.

DETAILED DESCRIPTION OF INVENTION AND PREFERRED EMBODIMENTS

In accordance with a convention used in the art,

is used in structural formulas herein to depict the bond that is the point of attachment of the moiety or substituent to the core or backbone structure.

As used herein, the term “aliphatic” represents a saturated or unsaturated, straight- or branched-chain hydrocarbon, containing 1 to 10 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described below. The term “aliphatic” is intended to encompass alkyl, alkenyl and alkynyl groups.

As used herein, the term “alkyl” represents a straight- or branched-chain saturated or unsaturated hydrocarbon, containing 1 to 10 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described below. Exemplary alkyl substituents include, but are not limited to methyl (Me), ethyl (Et), propyl, isopropyl, butyl, isobutyl, t-butyl, and the like. The term “lower alkyl” refers to an alkyl group containing from 1 to 6 carbon atoms

The term “alkenyl” represents a straight- or branched-chain hydrocarbon, containing one or more carbon-carbon double bonds and having 2 to 10 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described below. Exemplary alkenyl substituents include, but are not limited to ethenyl, propenyl, butenyl, allyl, pentenyl and the like.

The term “alkynyl” represents a straight- or branched-chain hydrocarbon, containing one or more carbon-carbon triple bonds and having 2 to 10 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described below. An alkynyl moiety may also contain one or more carbon-carbon double bonds. Exemplary alkynyl substituents include, but are not limited to ethynyl, butynyl, propynyl (propargyl) isopropynyl, pentynyl, hexynyl and the like.

The term “carbocyclic” represents a saturated, partially saturated, or fully unsaturated (aromatic) cyclic hydrocarbon group containing from 3 to 14 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described herein below. The term “carbocyclic” is intended to encompass mono-, bi- and tri-cyclic saturated, partially saturated, or fully unsaturated hydrocarbon groups; for example, cycloalkyl, cycloalkenyl and aryl groups. The term “carbocyclic” is also intended to encompass bi- and tri-cyclic hydrocarbon groups which contain any-combination of ring moieties that are saturated, partially saturated, or fully unsaturated (aromatic). Partially saturated carbocycles include, for example, dihydro-arenes (e.g., indanyl) or tetrahydro-arenes (e.g. tetrahydronaphthalene), wherein any one or more points of saturation may occur in any ring moiety of the carbocycle. In addition, it is understood that bonding between any bi- or tri-cyclic carbocyclic group and any other substituent or variable group may be made at any suitable position of the carbocycle. The term “carbocyclic-aliphatic” group is intended to encompass aliphatic groups having a carbocyclic substituent (e.g., phenylmethyl-(benzyl), phenylethyl-, cyclopropylmethyl-, etc.), wherein the carbocyclic moiety and the aliphatic moiety thereof may be independently substituted by one or more suitable substituents.

“Cycloalkyl” represents a group comprising a non-aromatic monocyclic, bicyclic, or tricyclic hydrocarbon containing from 3 to 14 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described below. Exemplary cycloalkyls include monocyclic rings having from 3-8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. Illustrative examples of cycloalkyl groups include the following:

“Cycloalkenyl” represents a group comprising a non-aromatic monocyclic, bicyclic, or tricyclic hydrocarbon containing from 4 to 14 carbon atoms which may be unsubstituted or substituted by one or more of the substituents described below and contains at least one carbon-carbon double bond. Exemplary monocyclic cycloalkenyls include groups having from 4-8, preferably 5-6, carbon atoms, such as cyclopentenyl, cyclopentadienyl, cyclohexenyl, cycloheptenyl and the like. Illustrative examples of cycloalkenyl groups include the following:

“Aryl” represents a group comprising an aromatic, monovalent monocyclic, bicyclic, or tricyclic radical containing from 6 to 18 carbon ring atoms, which may be unsubstituted or substituted by one or more of the substituents described below. Illustrative examples of aryl groups include the following:

The term “carbocyclic” also to encompasses mixed bi- and tri-cyclic cycloalkyl/cycloalkenyl/aryl groups, which may be unsubstituted or substituted by one or more of the substituents described below. Illustrative examples of such mixed bi- and tri-cyclic groups include the following:

It is understood that bonding or substitution of any bi-cyclic or tri-cyclic carbocyclic or heterocyclic group described herein may be at any suitable position on any ring.

Illustrative examples of such bonding in mixed bi- and tri-cyclic carbocyclic groups include the following:

wherein R′ is any suitable substituent.

The term “heterocyclic” represents a saturated, partially saturated, or fully unsaturated (aromatic) cyclic group containing from 3 to 18 ring atoms, which includes 1 to 5 heteroatoms selected from nitrogen, oxygen and sulfur, and which may be unsubstituted or substituted by one or more of the substituents described herein below. The term “heterocyclic” is intended to encompass mono-, bi- and tri-cyclic saturated, partially saturated, or fully unsaturated heteroatom-containing cyclic groups; for example, heterocycloalkyl, heterocycloalkenyl and heteroaryl groups. The term “heterocyclic” is also intended to encompass bi- and tri-cyclic groups which contain any combination of ring moieties that are saturated, partially saturated, or fully unsaturated (aromatic). Partially saturated heterocycles include, for example, dihydroheteroarenes (e.g., dihydroindole) or tetrahydro-heteroarenes (e.g. tetrahydroquinoline), wherein any one or more points of saturation may occur in any ring moiety of the heterocycle. In addition, it is understood that bonding between any bi- or tri-cyclic heterocyclic group and any other substituent or variable group may be made at any suitable position of the heterocycle (i.e., there is no restriction that a substituent or variable group must be bonded to the heteroatom-containing moiety of a bi- or tri-cyclic heterocyclic group). The term “heterocyclic-aliphatic” group is intended to encompass aliphatic groups having a heterocyclic substituent (e.g., pyridylmethyl-, thiazolylmethyl-, tetrahydrofuranylmethyl-, etc.) wherein the heterocyclic moiety and the aliphatic moiety thereof may be independently substituted by one or more suitable substituents.

“Heterocycloalkyl” represents a group comprising a saturated monovalent monocyclic, bicyclic, or tricyclic radical, containing 3 to 18 ring atoms, which includes 1 to 5 heteroatoms selected from nitrogen, oxygen and sulfur, and which may be unsubstituted or substituted by one or more of the substituents described below. Illustrative examples of heterocycloalkyl groups include, but are not limited to, azetidinyl, pyrrolidyl, piperidyl, piperazinyl, morpholinyl, tetrahydro-2H-1,4-thiazinyl, tetrahydrofuryl, tetrahydropyranyl, 1,3-dioxolanyl, 1,3-dioxanyl, 1,4-dioxanyl, 1,3-oxathiolanyl, 1,3-oxathianyl, 1,3-dithianyl, azabicylo[3.2.1]octyl, azabicylo[3.3.1]nonyl, azabicylo[4.3.0]nonyl, oxabicylo[2.2.1]heptyl, 1,5,9-triazacyclododecyl, and the like. Illustrative examples of heterocycloalkyl groups include the following:

-   -   wherein R is H, alkyl, hydroxyl or represents a compound         according to Formula I, and the bond depicted as         represents bonding to either face of the bi-cyclic moiety (i.e.,         endo or exo).

The term “heterocycloalkenyl” is used herein to represent a non-aromatic, monovalent monocyclic, bicyclic, or tricyclic radical, containing 4 to 18 ring atoms, which may include from 1 to 5 heteroatoms selected from nitrogen, oxygen and sulfur, and which may be unsubstituted or substituted by one or more of the substituents described below and which contains at least one carbon-carbon or carbon-heteroatom double bond. Exemplary monocyclic heterocycloalkenyls include groups having from 4-8, preferably 5-6, ring atoms. Illustrative examples of heterocycloalkenyl groups include, but are not limited to, dihydrofuryl, dihydropyranyl, isoxazolinyl, dihydropyridyl, tetrahydropyridyl, and the like. Illustrative examples of heterocycloalkenyl groups include the following:

-   -   wherein R is H, alkyl, hydroxyl or represents a compound         according to Formula I.

“Heteroaryl” represents a group comprising an aromatic monovalent monocyclic, bicyclic, or tricyclic radical, containing 5 to 18 ring atoms, including 1 to 5 heteroatoms selected from nitrogen, oxygen and sulfur, which may be unsubstituted or substituted by one or more of the substituents described below. As used herein, the term “heteroaryl” is also intended to encompass the N-oxide derivative (or N-oxide derivatives, if the heteroaryl group contains more than one nitrogen such that more than one N-oxide derivative may be formed) of the nitrogen-containing heteroaryl groups described herein. Illustrative examples of heteroaryl groups include, but are not limited to, thienyl, pyrrolyl, imidazolyl, pyrazolyl, furyl, isothiazolyl, furazanyl, isoxazolyl, thiazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, benzo[b]thienyl, naphtho[2,3-b]thianthrenyl, isobenzofuranyl, chromenyl, xanthenyl, phenoxathienyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, isoquinolyl, quinolyl, phthalazinyl, naphthyridinyl, quinoxyalinyl, quinzolinyl, benzothiazolyl, benzimidazolyl, tetrahydroquinolinyl, cinnolinyl, pteridinyl, carbazolyl, beta-carbolinyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, and phenoxazinyl. Illustrative examples of N-oxide derivatives of heteroaryl groups include, but are not limited to, pyridyl N-oxide, pyrazinyl N-oxide, pyrimidinyl N-oxide, pyridazinyl N-oxide, triazinyl N-oxide, isoquinolyl N-oxide, and quinolyl N-oxide. Further examples of heteroaryl groups include the following moieties:

wherein R is H, alkyl, hydroxyl or represents a compound according to Formula I.

The term “heterocyclic” also to encompasses mixed bi- and tri-cyclic heterocycloalkyl/heterocycloalkenyl/heteroaryl groups, which may be unsubstituted or substituted by one or more of the substituents described below. Illustrative examples of such mixed bi- and tri-cyclic heterocyclic groups include the following:

Illustrative examples of such bonding in mixed bi- and tri-cyclic heterocyclic groups include the following:

wherein R′ is any suitable substituent.

In the compounds of this invention, the alkyl, alkenyl and alkynyl groups may be optionally substituted by one or more suitable substituents independently selected from phenyl, nitro, amino, cyano, halogen, hydroxyl, alkoxy, haloalkoxy, aryloxy, cycloalkyloxy, cycloalkylalkyloxy, cycloalkenyloxy, cycloalkenylalkyloxy, heterocycloalkoxy, heterocycloalkylalkyloxy, heterocycloalkenyloxy, heterocycloalkenylalkyloxy, heteroaryloxy, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, alkyloxycarbonyl, alkenyloxycarbonyl, alkynyloxycarbonyl, alkylcarbonyloxy, alkenylcarbonyloxy, alkynylcarbonyloxy, arylcarbonyl, arylcarbonyloxy, aryloxycarbonyl, cycloalkylcarbonyl, cycloalkylcarbonyloxy, cycloalkyoxycarbonyl, heteroarylcarbonyl, heteroarylcarbonyloxy, heteroaryloxycarbonyl, heterocycloalkylcarbonyl, heterocycloalkylcarbonyloxy, heterocycloalkyoxycarbonyl, carboxyl, carbamoyl, formyl, keto (oxo), thioketo, sulfo, alkylamino, alkenylamino, alkynylamino, cycloalkylamino, cycloalkenylamino, arylamino, heterocycloalkylamino, heterocycloalkenylamino, heteroarylamino, dialkylamino, alkylaminocarbonyl, alkenylaminocarbonyl, alkynylaminocarbonyl, cycloalkylaminocarbonyl, cycloalkenylamino, arylaminocarbonyl, heterocycloalkylaminocarbonyl, heterocycloalkenylcarbonyl, heteroarylaminocarbonyl, dialkylaminocarbonyl, alkylaminothiocarbonyl, cycloalkylaminothiocarbonyl, arylaminothiocarbonyl, heterocycloalkylaminothiocarbonyl, heteroarylaminothiocarbonyl, dialkylaminothiocarbonyl, alkylsulfonyl, arylsulfonyl, alkylsulfenyl, arylsulfenyl, alkylcarbonylamino, cycloalkylcarbonylamino, arylcarbonylamino, heterocycloalkylcarbonylamino, heteroarylcarbonylamino, alkylthiocarbonylamino, cycloalkylthiocarbonylamino, arylthiocarbonylamino, heterocycloalkylthiocarbonylamino, heteroarylthiocarbonylamino, alkylsulfonyloxy, arylsulfonyloxy, alkylsulfonylamino, arylsulfonylamino, mercapto, alkylthio, haloalkylthio, arylthio and heteroarylthio groups, wherein any of the alkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, heteroaryl moieties present in the above substituents may be further substituted. The alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, and heteroaryl moieties of any of the above substituents may be optionally substituted by one or more groups independently selected from alkyl (except for alkyl), haloalkyl, aryl, nitro, amino, alkylamino, dialkylamino, halogen, hydroxyl, alkoxy, haloalkoxy, aryloxy, mercapto, alkylthio, haloalkylthio or arylthio groups.

In the compounds of this invention the substituted carbocyclic or heterocyclic groups may be optionally substituted by one or more suitable substituents independently selected from alkyl, haloalkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, heteroaryl, nitro, amino, cyano, halogen, hydroxyl, alkoxy, haloalkoxy, alkenyloxy, alkynyloxy, alkylenedioxy, aryloxy, cycloalkyloxy, cycloalkylalkyloxy, cycloalkenyloxy, cycloalkenylalkyloxy, heterocycloalkoxy, heterocycloalkylalkyloxy, heterocycloalkenyloxy, heterocycloalkenylalkyloxy, heteroaryloxy, alkylcarbonyl, alkyloxycarbonyl, alkylcarbonyloxy, arylcarbonyl, arylcarbonyloxy, aryloxycarbonyl, cycloalkylcarbonyl, cycloalkylcarbonyloxy, cycloalkyoxycarbonyl, heteroarylcarbonyl, heteroarylcarbonyloxy, heteroaryloxycarbonyl, heterocycloalkylcarbonyl, heterocycloalkylcarbonyloxy, heterocycloalkyoxycarbonyl, carboxyl, carbamoyl, formyl, keto (oxo), thioketo, sulfo, alkylamino, cycloalkylamino, arylamino, heterocycloalkylamino, heteroarylamino, dialkylamino, alkylaminocarbonyl, cycloalkylaminocarbonyl, arylaminocarbonyl, heterocycloalkylaminocarbonyl, heteroarylaminocarbonyl, dialkylaminocarbonyl, alkylaminothiocarbonyl, cycloalkylaminothiocarbonyl, arylaminothiocarbonyl, heterocycloalkylaminothiocarbonyl, heteroarylaminothiocarbonyl, dialkylaminothiocarbonyl, alkylsulfonyl, arylsulfonyl, alkylsulfenyl, arylsulfenyl, alkylcarbonylamino, cycloalkylcarbonylamino, arylcarbonylamino, heterocycloalkylcarbonylamino, heteroarylcarbonylamino, alkylthiocarbonylamino, cycloalkylthiocarbonylamino, arylthiocarbonylamino, heterocycloalkylthiocarbonylamino, heteroarylthiocarbonylamino, alkylsulfonyloxy, arylsulfonyloxy, alkylsulfonylamino, arylsulfonylamino, mercapto, alkylthio, haloalkylthio, arylthio and heteroarylthio groups, wherein any of the alkyl, alkylene, aryl, cycloalkyl, heterocycloalkyl, heteroaryl moieties present in the above substituents may be further substituted. Preferred “suitable substituents” include alkyl, alkenyl, alkynyl, aryl, cycloalkyl, heterocycloalkyl, heteroaryl, halogen, hydroxyl, alkoxy, alkylenedioxy, aryloxy, cycloalkoxy, heteroaryloxy, alkylthio, haloalkylthio and carboxyl. The alkyl, alkylene, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl moieties of any of the above substituents may be optionally substituted by one or more groups independently selected from: alkyl, haloalkyl, nitro, amino, alkylamino, dialkylamino, halogen, hydroxyl, alkoxy, haloalkoxy, mercapto, alkylthio, haloalkylthio or arylthio groups.

For example, in the compounds of this invention, the substituted phenyl or phenyl moiety of R² may comprise at least one substituent (other than halo or methyl) selected from haloalkyl, hydroxyalkyl, alkoxyalkyl, cycloalkoxyalkyl, alkylcarbonylalkyl, haloalkoxyalkyl, aryloxyalkyl, alkylthioalkyl, haloalkylthioalkyl, arylthioalkyl, cyanoalkyl, aminoalkyl, alkylaminoalkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, heteroaryl, nitro, amino, cyano, hydroxyl, alkoxy, haloalkoxy, alkenyloxy, alkynyloxy, alkylenedioxy, aryloxy, cycloalkyloxy, cycloalkylalkyloxy, cycloalkenyloxy, cycloalkenylalkyloxy, heterocycloalkoxy, heterocycloalkylalkyloxy, heterocycloalkenyloxy, heterocycloalkenylalkyloxy, heteroaryloxy, alkylcarbonyl, alkyloxycarbonyl, alkylcarbonyloxy, arylcarbonyl, arylcarbonyloxy, aryloxycarbonyl, cycloalkylcarbonyl, cycloalkylcarbonyloxy, cycloalkyoxycarbonyl, heteroarylcarbonyl, heteroarylcarbonyloxy, heteroaryloxycarbonyl, heterocycloalkylcarbonyl, heterocycloalkylcarbonyloxy, heterocycloalkyoxycarbonyl, carboxyl, carbamoyl, formyl, keto (oxo), thioketo, sulfo, alkylamino, cycloalkylamino, arylamino, heterocycloalkylamino, heteroarylamino, dialkylamino, alkylaminocarbonyl, cycloalkylaminocarbonyl, arylaminocarbonyl, heterocycloalkylaminocarbonyl, heteroarylaminocarbonyl, dialkylaminocarbonyl, alkylaminothiocarbonyl, cycloalkylaminothiocarbonyl, arylaminothiocarbonyl, heterocycloalkylaminothiocarbonyl, heteroarylaminothiocarbonyl, dialkylaminothiocarbonyl, alkylsulfonyl, arylsulfonyl, alkylsulfenyl, arylsulfenyl, alkylcarbonylamino, cycloalkylcarbonylamino, arylcarbonylamino, heterocycloalkylcarbonylamino, heteroarylcarbonylamino, alkylthiocarbonylamino, cycloalkylthiocarbonylamino, arylthiocarbonylamino, heterocycloalkylthiocarbonylamino, heteroarylthiocarbonylamino, alkylsulfonyloxy, arylsulfonyloxy, alkylsulfonylamino, arylsulfonylamino, mercapto, alkylthio, haloalkylthio, arylthio and heteroarylthio groups, wherein any of the alkyl, alkylene, aryl, cycloalkyl, heterocycloalkyl, heteroaryl moieties present in the above substituents may be further substituted. Preferred “suitable substituents” include alkyl, alkenyl, alkynyl, aryl, cycloalkyl, heterocycloalkyl, heteroaryl, halogen, hydroxyl, alkoxy, alkylenedioxy, aryloxy, cycloalkoxy, heteroaryloxy, alkylthio, haloalkylthio and carboxyl. The alkyl, alkylene, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl moieties of any of the above substituents may be optionally substituted by one or more groups independently selected from: alkyl, haloalkyl, nitro, amino, alkylamino, dialkylamino, halogen, hydroxyl, alkoxy, haloalkoxy, mercapto, alkylthio, haloalkylthio or arylthio groups.

If the substituents themselves are not compatible with the synthetic methods of this invention, the substituent may be protected with a suitable protecting group that is stable to the reaction conditions used in these methods. The protecting group may be removed at a suitable point in the reaction sequence of the method to provide a desired intermediate or target compound. Suitable protecting groups and the methods for protecting and de-protecting different substituents using such suitable protecting groups are well known to those skilled in the art; examples of which may be found in T. Greene and P. Wuts, Protecting Groups in Chemical Synthesis (3^(rd) ed.), John Wiley & Sons, NY (1999), which is incorporated herein by reference in its entirety. In some instances, a substituent may be specifically selected to be reactive under the reaction conditions used in the methods of this invention. Under these circumstances, the reaction conditions convert the selected substituent into another substituent that is either useful in an intermediate compound in the methods of this invention or is a desired substituent in a target compound.

In the compounds of this invention, R² and R^(2′), independently or taken together, may be a suitable nitrogen protecting group. As indicated above, nitrogen protecting groups are well known in the art and any nitrogen protecting group that is useful in the methods of preparing the compounds of this invention or may be useful in the HIV protease inhibitory compounds of this invention may be used. Exemplary nitrogen protecting groups include alkyl, substituted alkyl, carbamate, urea, amide, imide, enamine, sulfenyl, sulfonyl, nitro, nitroso, oxide, phosphinyl, phosphoryl, silyl, organometallic, borinic acid and boronic acid groups. Examples of each of these groups, methods for protecting nitrogen moieties using these groups and methods for removing these groups from nitrogen moieties are disclosed in T. Greene and P. Wuts, supra. Preferably, when R² and/or R^(2′) are independently suitable nitrogen protecting groups, suitable R² and R^(2′) substituents include, but are not limited to, carbamate protecting groups such as alkyloxycarbonyl (e.g., Boc: t-butyloxycarbonyl) and aryloxycarbonyl (e.g., Cbz: benzyloxycarbonyl, or FMOC: fluorene-9-methyloxycarbonyl), alkyloxycarbonyls (e.g., methyloxycarbonyl), alkyl or arylcarbonyl, substituted alkyl, especially arylalkyl (e.g., trityl (triphenylmethyl), benzyl and substituted benzyl), and the like. When R² and R^(2′) taken together are a suitable nitrogen protecting group, suitable R²/R^(2′) substituents include phthalimido and a stabase (1,2-bis (dialkylsilyl))ethylene).

The terms “halogen” and “halo” represent chloro, fluoro, bromo or iodo substituents. “Heterocycle” is intended to mean a heteroaryl or heterocycloalkyl group. “Acyl” is intended to mean a —C(O)—R radical, where R is a substituted or unsubstituted alkyl, cycloalkyl, aryl, heterocycloalkyl or heteroaryl group. “Acyloxy” is intended to mean an —OC(O)—R radical, where R is a substituted or unsubstituted alkyl, cycloalkyl, aryl, heterocycloalkyl or heteroaryl group. “Thioacyl” is intended to mean a —C(S)—R radical, where R is a substituted or unsubstituted alkyl, cycloalkyl, aryl, heterocycloalkyl or heteroaryl group. “Sulfonyl” is intended to mean an —SO₂— biradical. “Sulfenyl” is intended to mean an —SO— biradical. “Sulfo” is intended to mean an —SO₂H radical. “Hydroxy” is intended to mean the radical —OH. “Amine” or “amino” is intended to mean the radical —NH₂. “Alkylamino” is intended to mean the radical —NHR_(a), where R_(a) is an alkyl group. “Dialkylamino” is intended to mean the radical —NR_(a)R_(b), where R_(a) and R_(b) are each independently an alkyl group, and is intended to include heterocycloalkyl groups, wherein R_(a) and R_(b), taken together, form a heterocyclic ring that includes the amine nitrogen. “Alkoxy” is intended to mean the radical —OR_(a), where R_(a) is an alkyl group. Exemplary alkoxy groups include methoxy, ethoxy, propoxy, and the like. “Lower alkoxy” groups have alkyl moieties having from 1 to 4 carbons. “Alkoxycarbonyl” is intended to mean the radical —C(O)OR_(a), where R_(a) is an alkyl group. “Alkylsulfonyl” is intended to mean the radical —SO₂R_(a), where R_(a) is an alkyl group. “Alkylenedioxy” is intended to mean the divalent radical —OR_(a)O— which is bonded to adjacent atoms (e.g., adjacent atoms on a phenyl or naphthyl ring), wherein R_(a) is a lower alkyl group. “Alkylaminocarbonyl” is intended to mean the radical —C(O)NHR_(a), where R_(a) is an alkyl group. “Dialkylaminocarbonyl” is intended to mean the radical —C(O)NR_(a)R_(b), where R_(a) and R_(b) are each independently an alkyl group. “Mercapto” is intended to mean the radical —SH. “Alkylthio” is intended to mean the radical —SR_(a), where R_(a) is an alkyl group. “Carboxy” is intended to mean the radical —C(O)OH. “Keto” or “oxo” is intended to mean the diradical ═O. “Thioketo” is intended to mean the diradical ═S. “Carbamoyl” is intended to mean the radical —C(O)NH₂. “Cycloalkylalkyl” is intended to mean the radical -alkyl-cloalkyl, wherein alkyl and cycloalkyl are defined as above, and is represented by the bonding arrangement present in the groups —CH₂-cyclohexane or —CH₂-cyclohexene. “Arylalkyl” is intended to mean the radical -alkylaryl, wherein alkyl and aryl are defined as above, and is represented by the bonding arrangement present in a benzyl group. “Aminocarbonylalkyl” is intended to mean the radical -alkylC(O)NH₂ and is represented by the bonding arrangement present in the group —CH₂CH₂C(O)NH₂. “Alkylaminocarbonylalkyl” is intended to mean the radical -alkylC(O)NHR_(a), where R_(a) is an alkyl group and is represented by the bonding arrangement present in the group —CH₂CH₂C(O)NHCH₃. “Alkylcarbonylaminoalkyl is intended to mean the radical -alkylNHC(O)-alkyl and is represented by the bonding arrangement present in the group —CH₂NHC(O)CH₃. “Dialkylaminocarbonylalkyl” is intended to mean the radical -alkylC(O)NR_(a)R_(b), where R_(a) and R_(b) are each independently an alkyl group. “Aryloxy” is intended to mean the radical —OR_(c), where R_(c) is an aryl group. “Heteroaryloxy” is intended to mean the radical —OR_(d), where R_(d) is a heteroaryl group. “Arylthio” is intended to mean the radical —SR_(c), where R_(c) is an aryl group. “Heteroarylthio” is intended to mean the radical —SR_(d), where R_(d) is a heteroaryl group.

If an inventive compound is a base, a desired salt may be prepared by any suitable method known in the art, including treatment of the free base with an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like, or with an organic acid, such as acetic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic acid, oxalic acid, glycolic acid, salicylic acid, pyranosidyl acid, such as glucuronic acid or galacturonic acid, alpha-hydroxy acid, such as citric acid or tartaric acid, amino acid, such as aspartic acid or glutamic acid, aromatic acid, such as benzoic acid or cinnamic acid, sulfonic acid, such as p-toluenesulfonic acid or ethanesulfonic acid, or the like.

If an inventive compound is an acid, a desired salt may be prepared by any suitable method known to the art, including treatment of the free acid with an inorganic or organic base, such as an amine (primary, secondary, or tertiary); an alkali metal or alkaline earth metal hydroxide; or the like. Illustrative examples of suitable salts include organic salts derived from amino acids such as glycine and arginine; ammonia; primary, secondary, and tertiary amines; and cyclic amines, such as piperidine, morpholine, and piperazine; as well as inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum, and lithium.

Specific embodiments of the compounds of this invention comprising the compounds depicted by Formula I may also be described. For example, this invention relates to compounds useful for inhibiting the activity of HIV-protease of Formula I, above, wherein:

-   -   R¹ is a 5- or 6-membered monocyclic cycloalkyl, cycloalkenyl,         aryl, heterocycloalkyl, heterocycloalkenyl or heteroaryl group,         where said cycloalkyl, cycloalkenyl, aryl, heterocycloalkyl,         heterocycloalkenyl or heteroaryl group is unsubstituted or         substituted with one or more substituents independently selected         from alkyl, haloalkyl, amino, cyano, halogen, hydroxyl, alkoxy,         haloalkoxy, alkylenedioxy, di-haloalkylenedioxy, aryloxy,         cycloalkoxy, cycloalkylalkoxy, cycloalkenyloxy,         cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy,         heterocycloalkenyloxy, heterocycloalkenylalkoxy, heteroaryloxy,         alkylcarbonyloxy, arylcarbonyloxy, heteroarylcarbonyloxy,         alkylamino, dialkylamino, keto, alkylsulfonyl, arylsulfonyl,         alkylcarbonylamino, alkylthio, haloalkylthio and arylthio,         wherein any of the alkyl, alkylene, aryl, cycloalkyl,         heterocycloalkyl, heteroaryl moieties present in the above         substituents may be further substituted by one or more groups         independently selected from alkyl, haloalkyl, aryl, nitro,         amino, alkylamino, dialkylamino, halogen, hydroxyl, alkoxy,         haloalkoxy, aryloxy, mercapto, alkylthio, haloalkylthio and         arylthio groups;     -   R² is a substituted alkyl group, a substituted or unsubstituted         alkenyl group, or a substituted or unsubstituted alkynyl group,         wherein said alkyl, alkenyl or alkynyl group is a straight or         branched chained group, and     -   where said substituted alkyl, alkenyl or alkynyl group is         substituted by one or more substituents independently selected         from amino, cyano, halogen, hydroxyl, alkoxy, haloalkoxy,         aryloxy, cycloalkoxy, cycloalkylalkoxy, cycloalkenyloxy,         cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy,         heterocycloalkenyloxy, heterocycloalkenlalkoxy, heteroaryloxy,         alkylamino, dialkylamino, alkylsulfonyl, arylsulfonyl,         alkylsulfenyl, arylsulfenyl, alkylthio, haloalkylthio, arylthio         and heteroarylthio groups, wherein any of the alkyl, alkenyl,         alkynyl, aryl, cycloalkyl, cycloalkenyl, heterocycloalkyl,         heterocycloalkenyl, heteroaryl moieties present in the above         substituents may be further substituted by one or more groups         independently selected from alkyl, haloalkyl, halogen, hydroxyl,         alkoxy, haloalkoxy, alkylthio and haloalkylthio groups;     -   R^(2′) is H, methyl, ethyl or propyl, where said methyl, ethyl         or propyl is unsubstituted or substituted by halo or hydroxyl;     -   X is     -    wherein R^(x) is H or one or more substituents independently         selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy,         hydroxyl, alkylenedioxy, di-haloalkylenedioxy, alkylamino,         dialkylamino, alkylthio and haloalkylthio;     -   Z is S, O, SO, SO₂, CH₂ or CFH;     -   R³ is H;     -   R⁴, R⁵, R⁶ and R⁷ are independently selected from H or methyl;         and     -   R⁸ and R^(8′) are independently selected from H, halogen,         methyl, monohalo-methyl, dihalo-methyl and tri-halomethyl;     -   or a prodrug, pharmaceutically active metabolite or         pharmaceutically active salt or solvate thereof.

In more specific embodiments, this invention relates to compounds of Formula I, above, wherein:

-   -   R¹ is phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl,         thiazolyl, tetrahydrofuranyl, furanyl, thienyl or         tetrahydropyridazinyl, where said phenyl, pyrrolyl,         pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl,         tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl is         unsubstituted or substituted with one or more substituents         independently selected from alkyl, haloalkyl, halogen, and         hydroxyl;     -   R² is a substituted alkyl group, a substituted or unsubstituted         C₁-C₆ alkenyl group, or a substituted or unsubstituted C₁-C₆         alkynyl group, wherein said alkyl, alkenyl or alkynyl group is a         straight or branched chained group, and     -   where said substituted alkyl, alkenyl or alkynyl group is         substituted by one or more substituents independently selected         from cyano, halogen and alkylamino;     -   R^(2′) is H, methyl or ethyl;     -   X is     -    wherein R^(x) is H, halogen, or alkoxy;     -   Z is S, O, CH₂ or CFH;     -   R³, R⁴, R⁵, R⁸ and R^(8′) are each H; and     -   R⁶ and R⁷ are independently selected from H or methyl;     -   or a prodrug, pharmaceutically active metabolite or         pharmaceutically active salt or solvate thereof.

In preferred specific embodiments, this invention relates to compounds of Formula I, above, wherein:

-   -   R¹ is phenyl, where said phenyl is substituted with one or more         substituents independently selected from alkyl, halogen or         hydroxyl;     -   R² is a C₁-C₆ alkenyl group or a C₁-C₆ alkynyl group, wherein         said alkenyl or alkynyl group is a straight or branched chained         group, and     -   where said alkenyl or alkynyl group is unsubstituted or is         substituted by one or more halogen substituents;     -   R^(2′) is H;     -   X is     -    wherein R^(x) is H;     -   Z is S;     -   R³, R⁴, R⁵, R⁸ and R^(8′) are each H; and     -   R⁶ and R⁷ are each methyl;     -   or a prodrug, pharmaceutically active metabolite or         pharmaceutically active salt or solvate thereof.

More specifically, this invention relates to compounds useful for inhibiting the activity of HIV-protease of Formula I, above, wherein:

-   -   R¹ is a 5- or 6-membered mono-cyclic cycloalkyl, cycloalkenyl,         aryl, heterocycloalkyl, heterocycloalkenyl or heteroaryl group,         where said cycloalkyl, cycloalkenyl, aryl, heterocycloalkyl,         heterocycloalkenyl or heteroaryl group is unsubstituted or         substituted with one or more substituents independently selected         from alkyl, haloalkyl, amino, cyano, halogen, hydroxyl, alkoxy,         haloalkoxy, alkylenedioxy, dihaloalkylenedioxy, aryloxy,         cycloalkoxy, cycloalkylalkoxy, cycloalkenyloxy,         cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy,         heterocycloalkenyloxy, heterocycloalkenylalkoxy, heteroaryloxy,         alkylcarbonyloxy, arylcarbonyloxy, heteroarylcarbonyloxy,         alkylamino, dialkylamino, alkylsulfonyl, arylsulfonyl,         alkylcarbonylamino, alkylthio, haloalkylthio and arylthio,         wherein any of the alkyl, alkylene, aryl, cycloalkyl,         heterocycloalkyl, heteroaryl moieties present in the above         substituents are substituted by one or more groups independently         selected from alkyl, haloalkyl, aryl, nitro, amino, alkylamino,         dialkylamino, halogen, hydroxyl, alkoxy, haloalkoxy, aryloxy,         mercapto, alkylthio, haloalkylthio and arylthio groups;     -   R² is a substituted phenyl group, a substituted phenylalkyl         group, a substituted or unsubstituted phenylalkenyl group or a         substituted or unsubstituted phenylalkynyl group;     -   where said alkyl, alkenyl or alkynyl moiety of said phenylalkyl,         phenylalkenyl or phenylalkynyl group is a straight or branched         chain moiety;     -   R^(2′) is H, methyl, ethyl or propyl, where said methyl, ethyl         or propyl is unsubstituted or substituted with halo or hydroxyl;     -   X is     -    wherein R^(x) is H or one or more substituents independently         selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy,         hydroxyl, alkylenedioxy, di-haloalkylenedioxy, alkylamino,         dialkylamino, alkylthio and haloalkylthio;     -   Z is S, O, SO, SO₂, CH₂ or CFH;     -   R³ is H;     -   R⁴, R⁵, R⁶ and R⁷ are independently selected from H or methyl;         and     -   R⁸ and R^(8′) are independently selected from H, halogen,         methyl, monohalo-methyl, dihalo-methyl and tri-halomethyl;     -   provided that said 5- or 6-membered mono-cyclic         heterocycloalkyl, heterocycloalkenyl or heteroaryl group         contains at least two heteroatoms; or provided that said alkyl,         alkenyl or alkynyl moiety of said substituted phenylalkyl,         phenylalkenyl or phenylalkynyl group is substituted by one or         more substituents selected from halo or keto; or     -   provided that said substituted phenyl group or phenyl moiety of         said substituted phenylalkyl, phenylalkenyl or phenylalkynyl         group is substituted by one or more substituents other than halo         or methyl, where said one or more substituents is independently         selected from haloalkyl, hydroxyalkyl, alkoxyalkyl,         cycloalkoxyalkyl, alkylcarbonylalkyl, haloalkoxyalkyl,         aryloxyalkyl, alkylthioalkyl, haloalkylthioalkyl, arylthioalkyl,         cyanoalkyl, aminoalkyl, alkylaminoalkyl, alkenyl, alkynyl, aryl,         cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl,         heteroaryl, nitro, amino, cyano, hydroxyl, alkoxy, haloalkoxy,         alkenyloxy, alkynyloxy, alkylenedioxy, aryloxy, cycloalkoxy,         cycloalkylalkoxy, cycloalkenyloxy, cycloalkenylalkoxy,         heterocycloalkoxy, heterocycloalkylalkoxy, heterocycloalkenoxy,         heterocycloalkenylalkoxy, heteroaryloxy, alkylcarbonyl,         alkyloxycarbonyl, alkylcarbonyloxy, arylcarbonyl,         arylcarbonyloxy, aryloxycarbonyl, cycloalkylcarbonyl,         cycloalkylcarbonyloxy, cycloalkyoxycarbonyl, heteroarylcarbonyl,         heteroarylcarbonyloxy, heteroaryloxycarbonyl,         heterocycloalkylcarbonyl, heterocycloalkylcarbonyloxy,         heterocycloalkyoxycarbonyl, carboxyl, carbamoyl, formyl, keto,         thioketo, sulfo, alkylamino, cycloalkylamino, arylamino,         heterocycloalkylamino, heteroarylamino, dialkylamino,         alkylaminocarbonyl, cycloalkylaminocarbonyl, arylaminocarbonyl,         heterocycloalkylaminocarbonyl, heteroarylaminocarbonyl,         dialkylaminocarbonyl, alkylaminothiocarbonyl,         cycloalkylaminothiocarbonyl, arylaminothiocarbonyl,         heterocycloalkylaminothiocarbonyl, heteroarylaminothiocarbonyl,         dialkylaminothiocarbonyl, alkylsulfonyl, arylsulfonyl,         alkylsulfenyl, arylsulfenyl, alkylcarbonylamino,         cycloalkylcarbonylamino, arylcarbonylamino,         heterocycloalkylcarbonylamino, heteroarylcarbonylamino,         alkylthiocarbonylamino, cycloalkylthiocarbonylamino,         arylthiocarbonylamino, heterocycloalkylthiocarbonylamino,         heteroarylthiocarbonylamino, alkylsulfonyloxy, arylsulfonyloxy,         alkylsulfonylamino, arylsulfonylamino, mercapto, alkylthio,         haloalkylthio, arylthio and heteroarylthio groups, wherein any         of the alkyl, alkylene, aryl, cycloalkyl, heterocycloalkyl, or         heteroaryl moieties present in the above substituents are         unsubstituted or substituted by one or more groups independently         selected from alkyl, haloalkyl, halogen, hydroxyl, alkoxy,         haloalkoxy, alkylthio and haloalkylthio groups;     -   or a prodrug, pharmaceutically active metabolite or         pharmaceutically active salt or solvate thereof. If the phenyl         group or phenyl moiety of R² contains more than one substituent,         the substituents may be the same or different, and may be         independently selected from the above-described substituents.

More specifically, this invention relates to compounds useful for inhibiting the activity of HIV-protease of Formula I, above, wherein:

-   -   R¹ is phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl,         thiazolyl, tetrahydrofuranyl, furanyl, thienyl or         tetrahydropyridazinyl, where said phenyl, pyrrolyl,         pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl,         tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl is         unsubstituted or substituted with one or more substituents         independently selected from alkyl, haloalkyl, halogen, and         hydroxyl;     -   R² is a substituted phenylalkyl group, where said alkyl moiety         of said substituted phenylalkyl group is a straight or branched         chain alkyl moiety;     -   R^(2′) is H, methyl, ethyl or propyl, where said methyl, ethyl         or propyl is unsubstituted or substituted with hydroxyl;     -   X is     -    wherein R^(x) is H, halogen, or alkoxy;     -   Z is S, O, CH₂ or CFH;     -   R³, R⁴, R⁵, R⁸ and R^(8′) are each H; and     -   R⁶ and R⁷ are independently selected from H or methyl;     -   provided that R¹ is selected from isoxazolyl, pyrazolyl,         thiazolyl or tetrahydropyridazinyl, where said is isoxazolyl,         pyrazolyl, thiazolyl or tetrahydropyridazinyl is unsubstituted         or substituted with one or more substituents independently         selected from alkyl, haloalkyl, halogen, and hydroxyl when R² is         a substituted or unsubstituted phenylalkyl group or     -   provided that R¹ is selected from phenyl, pyrrolyl,         pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl,         tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl         when R² is a substituted phenylalkyl group and said phenyl         moiety of said substituted phenylalkyl group comprises one or         more substituents other than halo or methyl, where said one or         more substituents is independently selected from haloalkyl,         amino, hydroxyl, alkoxy, haloalkoxy, alkylenedioxy,         di-haloalkylenedioxy, cycloalkylalkyloxy, dialkylamino,         alkylsulfonyl and alkylthio;     -   or a prodrug, pharmaceutically active metabolite or         pharmaceutically active salt or solvate thereof.

In preferred embodiments, this invention relates to compounds of Formula I, above, wherein:

R¹ is phenyl, where said phenyl is substituted with one or more substituents independently selected from methyl, halogen or hydroxyl;

-   -   R² is a substituted phenylalkyl group, where said alkyl moiety         of said substituted phenylalkyl group is a straight or branched         chain alky moiety;     -   where said phenyl moiety of said substituted phenylalkyl group         comprises one or more substituents other than halo or methyl,         where said one or more substituents is independently selected         from trifluoromethyl, amino, hydroxyl, C₁-C₄alkoxy,         alkylenedioxy, di-fluoro-alkylenedioxy, cyclopropylmethoxy,         di-methyl-amino, methanesulfonyl and methylthio;     -   R^(2′) is H, methyl or ethyl;     -   X is     -    wherein R^(x) is H;     -   Z is S or O; and     -   R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R^(8′) are each H;     -   or a prodrug, pharmaceutically active metabolite or         pharmaceutically active salt or solvate thereof.

All compounds of this invention contain at least one chiral center and may exist as single stereoisomers (e.g., single enantiomers or single diastereomers), any mixture of stereosisomers (e.g., any mixture of enantiomers or diastereomers) or racemic mixtures thereof. All such single stereoisomers, mixtures and racemates are intended to be encompassed within the broad scope of the present invention. Compounds identified herein as single stereoisomers are meant to describe compounds that are present in a form that contains at least 90% of a single stereoisomer of each chiral center present in the compounds. Where the stereochemistry of the chiral carbons present in the chemical structures illustrated herein is not specified, the chemical structure is intended to encompass compounds containing either stereoisomer of each chiral center present in the compound. Preferably, however, the inventive compounds are used in optically pure, that is, stereoisomerically pure, form or substantially optically pure (substantially stereoisomerically pure) form. As used herein, the term “stereoisomeric” purity (or “optical” purity) refers to the “enantiomeric” purity and/or “diastereomeric” purity of a compound. Compounds that are substantially enantiomerically pure contain at least 90% of a single isomer and preferably contain at least 95% of a single isomer of each chiral center present in the enantiomer. Compounds that are substantially diastereomerically pure contain at least 90% of a single isomer of each chiral center present in the diastereomer, and preferably contain at least 95% of a single isomer of each chiral center. More preferably, the substantially enantiomerically and diastereomerically pure compounds in this invention contain at least 97.5% of a single isomer and most preferably contain at least 99% of a single isomer of each chiral center in the compound. The term “racemic” or “racemic mixture” refers to a mixture of equal amounts of enantiomeric compounds, which encompasses mixtures of enantiomers and mixtures of enantiomeric diastereomers. The compounds of this invention may be obtained in stereoisomerically pure (i.e., enantiomerically and/or diastereomerically pure) or substantially stereoisomerically pure (i.e., substantially enantiomerically and/or diastereomerically pure) form. Such compounds may be obtained synthetically, according to the procedures described herein using optically pure or substantially optically pure materials. Alternatively, these compounds may be obtained by resolution/separation of a mixture of stereoisomers, including racemic mixtures, using conventional procedures. Exemplary methods that may be useful for the resolution/separation of stereoisomeric mixtures include chromatography and crystallization/re-crystallization. Other useful methods may be found in “Enantiomers, Racemates, and Resolutions,” J. Jacques et al., 1981, John Wiley and Sons, New York, N.Y., the disclosure of which is incorporated herein by reference. Preferred stereoisomers of the compounds of this invention are described herein.

Especially preferred embodiments of this invention comprise compounds, wherein the stereogenic centers (chiral carbons) have the following designated stereochemistry:

More preferably, at least two of the stereogenic centers have the following designated stereochemistry:

Even more preferably, at least three of the stereogenic centers have the following designated stereochemistry:

Exemplary compounds of this invention include:

-   -   and the prodrugs, pharmaceutically active metabolites, and         pharmaceutically acceptable salts and solvates thereof.

The invention is also directed to the intermediates of Formula II, which are useful in the synthesis of certain compounds of Formula I:

The HIV protease inhibitor compounds of this invention include prodrugs, the pharmaceutically active metabolites, and the pharmaceutically acceptable salts and solvates thereof. In preferred embodiments, the compounds of Formula I, prodrugs, pharmaceutically acceptable salts, and pharmaceutically active metabolites and solvates thereof demonstrate an HIV-protease inhibitory activity, corresponding to K_(i) of at least 100 nM, an EC₅₀ of at least 10 mM or an IC₅₀ of at least 10 mM. Preferably, the compounds of this invention demonstrate an HIV-protease inhibitory activity, corresponding to a K_(i) of at least 10 nM, an EC₅₀ of at least 1 mM or an IC₅₀ of at least 1 mM. More preferably, the compounds of this invention demonstrate an HIV-protease inhibitory activity against mutant strains of HIV, corresponding to a K_(i) of at least 100 nM, an EC₅₀ of at least 10 mM or an IC₅₀ of at least 10 mM. Even more preferably, the compounds of this invention demonstrate protease inhibitory activity against mutant strains corresponding to a K_(i) of at least 10 nM, an EC₅₀ of at least 1 mM or an IC₅₀ of at least 1 mM.

A “prodrug” is intended to mean a compound that is converted under physiological conditions or by solvolysis or metabolically to a specified compound that is pharmaceutically active. A prodrug may be a derivative of one of the compounds of this invention that contains a moiety, such as for example —CO₂R, —PO(OR)₂ or —C═NR, that may be cleaved under physiological conditions or by solvolysis. Any suitable R substituent may be used that provides a pharmaceutically acceptable solvolysis or cleavage product. A prodrug containing such a moiety may be prepared according to conventional procedures by treatment of a compound of this invention containing, for example, an amido, carboxylic acid, or hydroxyl moiety with a suitable reagent. A “pharmaceutically active metabolite” is intended to mean a pharmacologically active compound produced through metabolism in the body of a specified compound. Prodrugs and active metabolites of compounds of this invention of the above-described Formulas may be determined using techniques known in the art, for example, through metabolic studies. See, e.g., “Design of Prodrugs,” (Bundgaard, ed.), 1985, Elsevier Publishers B.V., Amsterdam, The Netherlands. The following is an example of a prodrug that can be converted to the compound of this invention under physiological conditions, by solvolysis or metabolically:

A “pharmaceutically acceptable salt” is intended to mean a salt that retains the biological effectiveness of the free acids and bases of a specified compound and that is not biologically or otherwise undesirable. Examples of pharmaceutically acceptable salts include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, phosphates, monohydrogenphosphates, dihydrogenphosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, isobutyrates, caproates, heptanoates, propiolates, oxalates, malonates, succinates, suberates, sebacates, fumarates, maleates, butyne-1,4-dioates, hexyne-1,6-dioates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, sulfonates, xylenesulfonates, phenylacetates, phenylpropionates, phenylbutyrates, citrates, lactates, γ-hydroxybutyrates, glycollates, tartrates, methane-sulfonates (mesylates), propanesulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates, and mandelates. A “solvate” is intended to mean a pharmaceutically acceptable solvate form of a specified compound that retains the biological effectiveness of such compound. Examples of solvates include compounds of the invention in combination with water, isopropanol, ethanol, methanol, DMSO, ethyl acetate, acetic acid, or ethanolamine. In the case of compounds, salts, or solvates that are solids, it is understood by those skilled in the art that the inventive compounds, salts, and solvates may exist in different crystal forms, all of which are intended to be within the scope of the present invention and specified formulas.

The present invention is also directed to a method of inhibiting HIV protease activity, comprising contacting the protease with an effective amount of a compound of Formula I, or a pharmaceutically acceptable salt, prodrug, pharmaceutically active metabolite, or solvate thereof. For example, HIV protease activity may be inhibited in mammalian tissue by administering a compound of Formula I or a pharmaceutically acceptable salt, prodrug, pharmaceutically active metabolite, or solvate thereof. More preferably, the present method is directed at inhibiting HIV-protease activity. “Treating” or “treatment” is intended to mean at least the mitigation of a disease condition in a mammal, such as a human, that is alleviated by the inhibition of the activity of HIV proteases. The methods of treatment for mitigation of a disease condition include the use of the compounds in this invention in any conventionally acceptable manner, for example, as a prophylactic. The activity of the inventive compounds as inhibitors of HIV protease activity may be measured by any of the suitable methods known to those skilled in the art, including in vivo and in vitro assays. Examples of suitable assays for activity measurements are escribed herein. Administration of the compounds of the Formula I and their pharmaceutically acceptable prodrugs, salts, active metabolites, and solvates may be performed according to any of the generally accepted modes of administration available to those skilled in the art. Illustrative examples of suitable modes of administration include oral, nasal, parenteral, topical, transdermal, and rectal.

An inventive compound of Formula I or a pharmaceutically acceptable salt, prodrug, active metabolite, or solvate thereof may be administered as a pharmaceutical composition in any pharmaceutical form recognizable to the skilled artisan as being suitable. Suitable pharmaceutical forms include solid, semisolid, liquid, or lyophilized formulations, such as tablets, powders, capsules, suppositories, suspensions, liposomes, and aerosols. Pharmaceutical compositions of the invention may also include suitable excipients, diluents, vehicles, and carriers, as well as other pharmaceutically active agents, depending upon the intended use or mode of administration. Acceptable methods of preparing suitable pharmaceutical forms of the pharmaceutical compositions may be routinely determined by those skilled in the art. For example, pharmaceutical preparations may be prepared following conventional techniques of the pharmaceutical chemist involving steps such as mixing, granulating, and compressing when necessary for tablet forms, or mixing, filling, and dissolving the ingredients as appropriate, to give the desired products for oral, parenteral, topical, intravaginal, intranasal, intrabronchial, intraocular, intraaural, and/or rectal administration.

The present invention includes pharmaceutical compositions useful for inhibiting HIV protease, comprising an effective amount of a compound of this invention, and a pharmaceutically acceptable carrier. Pharmaceutical compositions useful for treating infection by HIV, or for treating AIDS or ARC, are also encompassed by the present invention, as well as a method of inhibiting HIV protease, and a method of treating infection by HIV, or of treating AIDS or ARC. Additionally, the present invention is directed to a pharmaceutical composition comprising a therapeutically effective amount of a compound of the present invention in combination with a therapeutically effective amount of an HIV infection/AIDS treatment agent selected from:

-   -   1) an HIV/AIDS antiviral agent,     -   2) an anti-infective agent, and     -   3) an immunomodulator.

The present invention also includes the use of a compound of the present invention as described above in the preparation of a medicament for (a) inhibiting HIV protease, (b) preventing or treating infection by HIV, or (c) treating AIDS or ARC.

The present invention further includes the use of any of the HIV protease inhibiting compounds of the present invention as described above in combination with one or more HIV infection/AIDS treatment agents selected from an HIV/AIDS antiviral agent, an anti-infective agent, and an immunomodulator for the manufacture of a medicament for (a) inhibiting HIV protease, (b) preventing or treating infection by HIV, or (c) treating AIDS or ARC, said medicament comprising an effective amount of the HIV protease inhibitor compound and an effective amount of the one or more treatment agents.

Solid or liquid pharmaceutically acceptable carriers, diluents, vehicles, or excipients may be employed in the pharmaceutical compositions. Illustrative solid carriers include starch, lactose, calcium sulfate dihydrate, terra alba, sucrose, talc, gelatin, pectin, acacia, magnesium stearate, and stearic acid. Illustrative liquid carriers include syrup, peanut oil, olive oil, saline solution, and water. The carrier or diluent may include a suitable prolonged-release material, such as glyceryl monostearate or glyceryl distearate, alone or with a wax. When a liquid carrier is used, the preparation may be in the form of a syrup, elixir, emulsion, soft gelatin capsule, sterile injectable liquid (e.g., solution), or a nonaqueous or aqueous liquid suspension. A dose of the pharmaceutical composition contains at least a therapeutically effective amount of the active compound (i.e., a compound of Formula I or a pharmaceutically acceptable salt, prodrug, active metabolite, or solvate thereof), and preferably is made up of one or more pharmaceutical dosage units. The selected dose may be administered to a mammal, for example, a human patient, in need of treatment mediated by inhibition of HIV protease activity, by any known or suitable method of administering the dose, including: topically (for example, as an ointment or cream), orally, rectally (for example, as a suppository), parenterally (by injection) or continuously by intravaginal, intranasal, intrabronchial, intraaural, or intraocular infusion. A “therapeutically effective amount” is intended to mean the amount of an inventive agent that, when administered to a mammal in need thereof, is sufficient to effect treatment for disease conditions alleviated by the inhibition of the activity of one or more variant of the HIV protease. The amount of a given compound of the invention that will be therapeutically effective will vary depending upon factors such as the particular compound, the disease condition and the severity thereof, the identity of the mammal in need thereof, which amount may be routinely determined by artisans.

The compounds of this invention are also useful in the preparation and execution of screening assays for antiviral compounds. For example, the compounds of this invention are useful for isolating enzyme mutants that are excellent screening tools for more powerful antiviral compounds. Furthermore, the compounds of this invention are useful in establishing or determining the binding site of other antivirals to HIV protease, e.g., by competitive inhibition. Thus the compounds of this invention are commercial products to be sold for these purposes.

General Synthetic Methods

Preferably, the inventive compounds are prepared by the methods of the present invention, including the General Methods shown below. When stereochemistry is not specified in chemical structures, either stereocenter may be utilized. The following abbreviations also apply: Boc (tert-butoxycarbonyl), Ac (acetyl), Cbz (benzyloxycarbonyl), DMB (2,4-dimethoxybenzyl), TBS (tert-butyldimethylsilyl), TBDPS (tert-butyldiphenylsilyl), Ms (methanesulfonate), Ts (toluenesulfonate), Bn (benzyl), and Tr (triphenylmethyl)

All reactions were performed in septum-sealed flasks under a slight positive pressure of argon unless otherwise noted. All commercial reagents and solvents were used as received from their respective suppliers with the following exceptions: Tetrahydrofuran (THF) was distilled from sodium benzophenone ketyl prior to use. Dichloromethane (CH₂Cl₂) was distilled from calcium hydride prior to use. Flash chromatography was performed using silica gel 60 (Merck art. 9385). ¹H NMR spectra were recorded at 300 MHz utilizing a Varian UNITYplus 300 spectrometer. Chemical shifts are reported in ppm (δ) downfield relative to internal tetramethylsilane, and coupling constants are given in Hertz. Infrared absorption spectra were recorded using a Perkin-Elmer 1600 series FTIR spectrometer. Elemental analyses were performed by Atlantic Microlab, Inc., Norcross, Ga. Melting points are uncorrected.

All P2′ amine variants mentioned in General Methods A-E described hereinbelow were either purchased and used directly or synthesized as follows. Method A: Representative Procedure for Reduction of Ketones to Alcohols.

6,7-Dihydro-4-(5H)-benzofuranone (1) (1.00 g 7.34 mmol) was dissolved in methanol (55 mL). The mixture was cooled to 0° C. and NaBH (0.31 g, 8.08 mmol) was added in portions. The reaction was stirred for 2 h at 0° C. at which time the methanol was evaporated. The residue was dissolved in EtOAc and poured into NaHCO₃ (saturated aqueous) and extracted with EtOAc (3×10 mL). The combined organic extracts were washed with brine (10 mL), passed over a short plug of Na₂SO₄, and concentrated in vacuo to give 2 (1.01 g, 99%, as a mixture of isomers) as a pale yellow, thick oil, which was of sufficient quality to be advanced to the next step without further purification. Rf (50% EtOAc/hexanes): 0.53. Method B: Representative Procedure for Reduction of Acids to Alcohols.

Tiglic acid (1) (20.0 g, 0.200 mol) was dissolved in ether (80 ml) and added dropwise over 30 min to a suspension of LiAlH₄ (15.0 g, 0.417 mol) in ether (80 ml) at 0° C. and the reaction mixture was allowed to warm to room temperature. After 3 h the mixture was re-cooled to 0° C. and quenched slowly by the addition of H₂O (15 ml), 15% NaOH (15 ml) and H₂O (15 ml). The reaction mixture was filtered to remove the granular precipitate and washed thoroughly with ether. The filtrate was washed successively with 1N HCl, NaHCO₃ (saturated aqueous), and brine. The combined organic layers were dried over MgSO₄ and concentrated in vacuo to give (E)-2-methyl-but-2-en-1-ol (2) as a clear oil (12.8 g, 74%). Method C: Representative Procedure for Alkylation of Phenols Alcohols.

3-Hydroxybenzylalcohol (1) (0.500 g 4.03 mmol) was dissolved in DMF (2 mL) at ambient temperature. Ethyl bromide (0.900 mL, 12.1 mmol) and finely crushed K₂CO₃ (2.78 g, 20.1 mmol) were added and the reaction mixture was stirred for 5 h. The DMF was then removed in vacuo and the residue was partitioned between EtOAc and H₂O, and extracted with EtOAc (3×10 mL). The organic layers were washed with brine (10 mL) and passed over a short plug of Na₂SO₄. The solvents were removed in vacuo to give alcohol 2 (0.55 g, 90%) as a pale yellow, thick oil, which was of sufficient quality to be advanced to the next step without further purification. Rf (40% EtOAC/hexanes): 0.69. Method D: Representative Procedure for Conversion of Alcohols to Amines.

3-Ethoxy-phenyl-methanol (1) (1.23 g 8.08 mmol) was dissolved in CH₂Cl₂ (10 mL) at ambient temperature and diphenylphosphoryl azide (2.67 g, 9.70 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (1.45 mL, 9.70 mmol) were added. The mixture was stirred for 5 h at which time the CH₂Cl₂ was removed in vacuo and the crude residue was partitioned between EtOAc and H₂O and extracted with EtOAc (3×10 mL). The combined organic layers were washed with brine (10 mL), passed over a short plug of Na₂SO₄, and concentrated in vacuo to give a yellow oil that was loaded directly onto a flash silica gel column and was quickly eluted with 10% EtOAc/hexanes. The solvents were removed in vacuo to give azide 2 (1.43 g, 84%) as a colorless oil Rf (30% EtOAc/hexanes): 0.79.

1-Azidomethyl-3-ethoxy-benzene (2) (1.19 g 6.71 mmol) was dissolved in MeOH (15 mL) and palladium 10% on activated carbon, wet (20% in weight) was added. The reaction was hydrogenated for 30 min at 40 PSI in a Parr Hydrogenator. The black suspension was then filtered through compacted celite and the methanol was removed in vacuo to give amine 3 (0.88 g, 88%) as a pale yellow, thick oil, which was of sufficient quality to be advanced to the coupling reactions without further purification. Method E: Representative Procedure for Conversion of Alcohols to Bromides.

Cis-2-penten-1-ol (1) (1.00 g, 11.6 mmol) and carbon tetrabromide (3.85 g, 13.9 mmol) were dissolved in CH₂Cl₂ (75 mL). The mixture was cooled to 0° C. and triphenylphosphine (3.65 mL, 13.9 mmol) dissolved in CH₂Cl₂ (50 mL) was added dropwise. The mixture was allowed to warm to room temperature and was stirred overnight. The CH₂Cl₂ was removed in vacuo and the crude residue was loaded directly onto a flash silica gel column and eluted quickly with 20% EtOAc/hexanes. The solvents were removed in vacuo to give bromide 2 (1.53 g, 88%) as a colorless volatile oil. Rf (30% EtOAC/hexanes): 0.89. Method F: Representative Procedure for Conversion of Bromides to Amines.

A mixture of bromide 1 (3.00 g, 20.1 mmol), di-tert-butyl-iminodicarboxylate (4.8 g, 22 mmol), and K₂CO₃ (3.10 g, 80.4 mmol) in DMF (30 ml) was stirred at ambient temperature overnight. The mixture was partitioned between 1N HCl and EtOAc. The organic layer was washed with H₂O and brine, then dried over NaSO₄. Concentration in vacuo affored a yellow oil which upon purification by flash column chromatography (hexanes to 5% EtOAc/Hexane gradient) yielded protected amine 2 as a clear oil (2.0 g, 35%).

A mixture of the diBOC amine 2 (2.0 g, 7.0 mmol), trifluoroacetic acid (2.7 ml, 35 mmol) and CH₂Cl₂ (40 ml) was stirred at ambient temperature overnight. The reaction mixture was concentrated in vacuo to give the TFA salt of (E)-2-methyl-but-2-enylamine (3). Method G: Representative Procedure for Reduction of Aromatic Nitro Groups by Hydrogenation.

Compound 1 (2.04, 5.79 mmol) was dissolved in EtOAc (20 mL) and palladium 10% on activated carbon, wet (20% in weight) was added. The reaction was hydrogenated for 4 h at 45 PSI in a Parr Hydrogenator. The black suspension was then filtered through compacted celite and the methanol was removed in vacuo to give aniline 2 (1.65 g, 88%) as a pale yellow, thick oil, which was of sufficient quality to be advanced to the acetylation reaction without further purification. Method H: Representative Procedure for Acetylation of Anilines.

Aniline 1 (1.65 g, 5.12 mmol) was dissolved in CH₂Cl₂ (25 mL) at ambient temperature. Acetyl chloride (0.48 g, 6.14 mmol) and N,N-Diisopropylethylamine (0.79 g, 6.14 mmol) were added, and the reaction was stirred overnight. The CH₂Cl₂ was removed in vacuo and the crude residue was partitioned between EtOAc and 5% KHSO₄ and extracted with EtOAc (3×10 mL). The combined organic extracts were washed with NaHCO₃ (saturated aqueous, 10 mL), brine (10 mL), and dried over Na₂SO₄. The solvents were removed in vacuo to give an orange oil which was of sufficient quality to be advanced to the next step without further purification. Rf (50% EtOAC/hexanes): 0.42. Method I: Representative Procedure for Reduction of Aldehydes to Amines.

Hydroxylamine hydrochloride (758 mg, 10.7 mmol) and pyridine (2.16 mL) was added to a solution of 2,2-difluoro-5-formyl benzodioxole (1) (2.00 g, 10.7 mmol) in MeOH (10 mL). After 18 hours the MeOH was removed in vacuo. The reaction mixture was diluted with EtOAc and was washed sequentially with H₂O, 10% W/V CuSO₄, and brine and then dried over MgSO₄. The solution was concentrated in vacuo. The hydroxy imine was purified by column chromatography using 20% EtOAc/Hexanes to give 1.37 g (64% yield) of a white solid. Imine was then subjected to LAH reduction as described above to provide amine 3.

The following amines were synthesized for the corresponding example numbers:

EXAMPLE A26

Amine was generated by alkylation of 3-hydroxybenzyl alcohol with ethyl bromide as describe in method C above followed by conversion of the alcohol to the amine as described in method D above provided desired amine.

EXAMPLE A43

Amine was generated as described above for Example A43 using propylbromide as the alkylating agent

EXAMPLE A33

Amine was generated from displacement of bromide in 3-nitrobenzylbromide with di BOC amine as described in method F above. Reduction of the nitro moiety to the aniline (method G above) followed by acetylation (method H above) and BOC removal (method F above) provided desired amine.

EXAMPLE A36, EXAMPLE A37 And EXAMPLE A40

Amines were generated from conversion of the corresponding primary alcohols as described in method E above. Displacement of the bromide with di BOC amine and deprotection with TFA (method F above) provided the desired amines.

EXAMPLE A39

Amine was generated from 3-dimethylaminobenzyl alcohol as described in method D above.

EXAMPLE A34

Amine was generated by reduction of the corresponding methyl ester to the primary alcohol (Wipf, J. Org Chem. 1994, 59, 4875-86.). Conversion to the bromide (method E above) followed by displacement with diBOC amine and deprotection (method F above) provided desired amine.

EXAMPLE A35

Amine was generated from the corresponding carboxylic acid. Reduction of the acid as described in method B above followed by bromide displacement as described in method E above gave the primary bromide. Conversion of the bromide to the primary amine followed the procedure described in method F above.

EXAMPLE A42

Amine was generated from 3-benzyloxybenzyl alcohol. Conversion to the azide and reduction of both the azide and benzyl protecting group were accomplished using method D as described above with longer hydrogenation time.

EXAMPLE A44

Amine was generated by LiAlH₄ reduction of 2-cyanophenol (Ludeman, S. M., et. al. J. Med. Chem. 1975, 18, 1252-3.).

EXAMPLE A50

Amine was generated from the condensation of o-tolualdehyde with 2-aminoethanol followed by reduction with sodium borohydride (Tetrahedron Assym. 1997, 8, 2367-74.).

EXAMPLE A48

Amine was generated from the corresponding aldehyde by the reductive amination procedure described in method I above.

EXAMPLE A7

Amine was generated by a reductive amination with the corresponding aldehyde (Arch. Pharm. 1987, 320, 647-54.).

EXAMPLE A49

Amine was generated on the thiazolidine core as follows:

Diphenylchlorophosphate (1.0 ml, 4.2 mmol) followed by triethylamine (0.59 ml, 4.2 mmol) were added to a cooled 0° C. solution of BOC-DMTA 1 (1.0 g, 3.8 mmol) in EtOAc (10 ml). The mixture was stirred for 1 h and at which time triethylamine (0.59 ml, 4.2 mmol) and ethanolamine (0.25 ml, 4.2 mmol) were added. The reaction was left to stir overnight at ambient temperature and then partitioned between 1N HCl and EtOAc. The organic layer was washed with NaHCO₃(saturated aqueous) and brine. The organic layer was dried over Na₂SO₄ and concentrated in vacuo to a pale yellow oil 2. The oil was stirred with thionyl chloride (2 ml) for 45 min at room temperature. The mixture was concentrated in vacuo and the residual oil was partitioned between 1N NaOH and EtOAc. The organic layer was extracted with 1N HCl (2×20 ml). The combined aqueous layers were made basic with 1N NaOH and then extracted with EtOAc (3×60 ml). The organic layers were washed with brine, dried over Na₂SO₄ and concentrated in vacuo to give (R)-5,5-Dimethyl-thiazolidine-4-carboxylic acid (2-chloro-ethyl)-amide 3 as a clear oil (0.39 g, 55%).

The following amines were prepared as described:

EXAMPLE A31 EXAMPLE A32 EXAMPLE A38

The above amines were prepared according to Carlsen, H. J., J. Heterocycle Chem. 1997, 34, 797-806.

EXAMPLE A41

The above amine was prepared according to O'Brien, P. M., J. Med. Chem. 1994, 37, 1810-1822.

EXAMPLE A7

The above amine was prepared according to Weinheim, G. Arch. Pharm. 1987, 320, 647-654.

The synthesis of compounds with the general structure 5 is as follows. The boc-protected thiazolidine carboxylic acid 1 is coupled to the requisite amines 2 to yield amino amides 3 using a two step process. The process includes treatment of 1 with 2 in the presence of either diphenylchlorophosphate or HATU, followed by exposure to methane sulfonic acid. Final compounds 5 are obtained by a DCC-mediated coupling of 3 and 4 followed by deprotection of the P2 phenol. Final compounds were purified either by flash chromatography or preparative HPLC.

An alternative approach to the general structure 5 is as follows. The thiazolidine ester 6 is coupled to acid 7 under carbodiimide reaction conditions, resulting in product 8 which is converted to acid 9 by mild base hydrolysis. Acid 9 is combined with various amines, using diphenylphosphoryl azide, followed by cleavage of the P2 acetate to yield final compounds 5. The products were purified by either flash chromatography or preparative HPLC.

EXAMPLE A1 3-[2-Hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid, (1,2,3,4-tetrahydro-naphthalen-1-yl)-amide

The title compound was prepared as follows. (R)-5,5-Dimethyl-thiazolidine-3,4-dicarboxylic acid 3-tert-butyl ester 1 (0.3 g, 1.15 mmol) was dissolved in EtOAc (3 mL) and cooled to 0° C. Diphenyl chlorophosphate (0.26 mL, 1.26 mmol) was added followed by TEA (0.18 mL, 1.26 mmol). The reaction was stirred at 0° C. for 1 h, and treated with (S)-1,2,3,4-Tetrahydro-1-naphthylamine (0.19 g, 1.26 mmol). The reaction mixture was stirred at room temperature overnight, then partitioned between 1N HCl (5 mL) and EtOAc (10 mL). The organic layer was washed with saturated NaHCO₃, brine, dried over Na₂SO₄ and concentrated to a light yellow oil. The resulting crude oil was dissolved in EtOAc (5 mL) and the cooled to 0° C. Methanesulfonic acid (0.36 mL, 5.32 mmol) was added and the solution was stirred at 0° C. for 15 minutes, then at room temperature for 1 h. The mixture was re-cooled to 0° C. and quenched with 5% Na₂CO₃ (5 mL) then extracted with EtOAc (10 mL). The organic layer was washed with brine, dried over Na₂SO₄ and concentrated in vacuo to give 3a as a yellow oil. The yellow oil 3a (0.34 g, 1.15 mmol) was dissolved in EtOAc (12 mL). AMB-AHPBA 4 (0.40 g, 1.09 mmol) was added followed by HOBt (0.15 g, 1.09 mmol). The mixture was stirred at room temperature 1 h, then cooled to 0° C. DCC (0.24 g, 1.15 mmol) was slowly added as solution in EtOAc (6 mL). The mixture was warmed to room temperature and stirred overnight. The mixture was filtered and the filtrate was washed with 1N HCl (10 mL), saturated NaHCO₃ (10 mL), brine (10 mL), dried over Na₂SO₄ and concentrated to give a crude white solid (contaminated with DCU). The DCU was removed by flash chromatography (30% to 50% EtOAc in hexanes) to provide a white solid, which was dissolved in MeOH (2 mL) and treated with 4N HCl in 1,4-dioxane (0.26 mL, 1.1 mmol). The reaction was stirred at room temperature overnight then partitioned between 1N HCl (10 mL) and EtOAc (10 mL). The organic layer was washed with saturated NaHCO₃, dried over Na₂SO₄ and concentrated to a residue which was purified by flash chromatography (60% EtOAc in hexanes) to provide the title compound as a white solid: mp=125-126° C.; IR (cm⁻¹) 3320, 2932, 1704, 1644, 1530, 1454, 1361, 1284; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.28 (d, J=8.6, 1H), 8.21 (d, J=8.8, 1H), 7.35-6.91 (m, 10H), 6.76 (d, J=8.0, 1H), 6.54 (d, J=7.5, 1H), 5.34 (d, J=6.0, 1H), 5.13 (d, J=9.0, 1H), 5.02 (d, J=9.0, 1H), 4.60-4.30 (m, 4H), 2.81-2.68 (m, 4H), 1.81 (s, 3H), 1.78-1.60 (m, 4H), 1.48 (s, 3H), 1.45 (s, 3H); Anal. Calcd for C₃₄H₃₉N₃O₅S.1.5H₂O: C, 64.95; H, 6.73; N, 6.68. Found: C, 64.88; H, 6.31; N, 6.18.

EXAMPLE A2 (R)-3-((2S,3R)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-methoxy-benzylamide

White solid: mp=108-110° C.; IR (neat, cm⁻¹) 3310, 2965, 1644, 1586, 1531, 1455, 1359, 1284; ¹HNMR (DMSO-d₆) δ 9.37 (s, 1H), 8.40 (t, J=6.0, 1H), 8.09 (d, J=8.1, 1H), 7.31-6.52 (m, 12H), 5.49 (d, J=6.0, 1H), 5.12 (d, J=9.3, 1H), 5.00 (d, J=9.3, 1H), 4.44-4.35 (m, 3H), 4.42 (s, 1H), 4.09 (dd, J=15.0, 6.0, 1H), 3.69 (s, 3H), 2.87-2.67 (m, 2H), 1.82 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. Calcd for C₃₂H₃₇N₃O₆S.0.75H₂O: C, 63.50; H, 6.41; N, 6.94. Found: C, 63.60; H, 6.23; N, 6.80.

The following examples were prepared by the specific method outlined above using the requisite amine 2.

EXAMPLE A3 (R)-3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methoxy-benzylamide

White solid: mp=123-125° C.; IR (cm⁻¹) 3318, 2965, 1644, 1525, 1495, 1464, 1286, 1246, 1120, 1030; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.26 (t, J=5.9, 1H), 8.14 (d. J=8.0, 1H), 7.39-7.13 (m, 6H), 6.95-6.76 (m, 5H), 6.53 (d, J=7.5, 1H), 5.49 (d, J=6.0, 1H), 5.13 (d, J=9.0, 1H), 5.01 (d, J=9.0, 1H), 4.47 (s, 1H), 4.41-4.16 (m, 4H), 3.78 (s, 3H) 2.90-2.62 (m, 2H), 1.81 (s, 3H), 1.49 (s, 3H). 1.32 (s, 3H); Anal. Calcd for C₃₂H₃₇N₃O₆S.0.75H₂O: C, 63.50; H, 6.41; N, 6.94. Found: C, 63.68; H, 6.20; N, 6.54.

EXAMPLE A4 3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-trifluoromethyl-benzylamide

White solid: mp=108-110° C.; IR (cm⁻¹) 3308, 3065, 1646, 1540, 1456, 1362, 1329, 1284, 1165, 1125, 1074; ¹H NMR (DMSO-d₆) δ 9.38 (s, 1H), 8.56 (t, J=6.0, 1H), 8.12 (d, J=8.2, 1H), 7.65 (s, 1H), 7.60-7.47 (m, 3H), 7.28-7.13 (m, 5H), 6.96-6.92 (m, 1H), 6.77 (d, J=8.0, 1H), 6.53 (d, J=7.5, 1H), 5.45 (d, J=6.0, 1H), 5.14 (d, J=9.2, 1H), 5.00 (d, J=9.2, 1H), 4.53-4.41 (m, 4H), 4.22 (dd, J=16.0, 6.0, 1H), 2.86-2.66 (m, 2H), 1.81 (s, 3H), 1.49 (s, 3H), 1.31 (s, 3H); Anal. Calcd for C₃₂H₃₄F₃N₃O₅S: C, 61.04; H, 5.44; N, 6.67. Found: C, 61.03; H, 5.56; N, 6.51.

EXAMPLE A5 3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methyanoyl]amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxlic acid fluoro trifluoromethyl-benzylamide

¹H NMR (DMSO-d₆) δ 9.33 (s, 1H), 8.69 (t, J=5.6, 1H), 8.12-6.56 (m, 1H), 5.50 (d, J=6.0, 1H), 5.22 (d, J=9.3, 1H), 5.06 (d, J=9.3, 1H), 4.60-4.36 (m, 5H), 4.50 (s, 1H), 2.89-2.67 (m, 2H), 1.83 (s, 3H), 1.55 (s, 3H), 1.39 (s, 3H); Anal. Calcd for C₃₂H₃₃N₃O₅SF₄: C, 59.34; H, 5.14; N, 6.49; S, 4.95. Found: C, 59.06; H, 5.31; N, 6.22; S, 4.66.

EXAMPLE A6 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 4-methoxy-benzylamide

IR (neat cm⁻¹) 3335, 2920, 1641, 1516, 1463, 1374, 1285, 1249, 1172, 1118; ¹H NMR (DMSO-_(d6)) δ 9.38 (s, 1H), 8.37 (t, J=5.5, 1H), 8.12 (d, J=8.2, 1H), 7.33-7.13 (m, 7H), 6.94 (t, J=7.7, 1H), 6.84-6.79 (m, 3H), 6.54 (d, J=7.0, 1H), 5.48 (d, J=6.6, 1H), 5.12 (d, J=9.2, 1H), 5.00 (d, J=9.2, 1H), 4.49-4.42 (m, 3H), 4.32 (dd, J=6.2, 14.8, 6, 1H), 4.09 (dd, J=14.8, 5.3, 1H), 3.67 (s, 3H), 2.87-2.68 (m, 2H), 1.82 (s, 3H), 1.48 (s, 3H), 1.32 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₇N₃O₆SNa (M+Na)⁺ 614.2301, found 614.2305; Anal. Calcd for C₃₂H₃₇N₃O₆S.0.75H₂O: C, 63.50; H, 6.41; N, 6.94. Found: C, 63.65; H, 6.43; N, 6.74.

EXAMPLE A7 3-[2-Hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiiazolidine-4-carboxylic acid methyl-(2-methyl-benzyl)-amide

¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.44 (t, J=7.98, 1H), 8.13-8.07 (m, 2H), 7.34-7.13 (m, 9H), 6.93 (t, J=7.9, 1H), 6.78 (d, J=7.7, 1H), 6.53 (d, J=7.1, 1H), 5.58 (d, J=6.8, 1H), 5.45 (d, J=7.0, 1H), 5.12 (dd J=7.8 8.2 1H), 4.51-4.31 (m, 6H), 2.86-2.67 (m, 2H), 2.19 (s, 3H), 1.81 (s, 3H), 1.51 (s, 3H), 1.34 (s, 3H); Anal. Calcd for C₃₃H₃₉N₃O₅S.0.37H₂O: C, 66.45; H, 6.72; N, 7.15. Found: C, 66.34; H, 7.28; N, 7.45.

EXAMPLE A8 3-[2-Hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiiazolidine-4-carboxylic acid methyl-(3-methyl-thiophen-2-ylmethyl)-amide

IR (neat or KBr cm⁻¹) 3150, 3000, 2942, 2187, 1712, 1600, 1567, 1505; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.44 (t, J=7.98, 1H), 8.13-8.07 (m, 2H), 7.34-7.13 (m, 5H), 6.93 (t, J=7.9, 1H), 6.78 (d, J=7.7, 1H), 6.53 (d, J=7.1, 1H), 5.45 (d, J=7.0, 1H), 5.12 (dd, J=7.8, 8.2 1H), 4.51-4.31 (m, 4H), 2.86-2.67 (m, 2H), 2.19 (s, 3H), 1.81 (s, 3H), 1.51 (s, 3H), 1.34 (s, 3H); Anal. Calcd for C₃₀H₃₅N₃O₅S₂: calculated C, 61.94 H, 6.06 N, 7.22. Found C, 62.38 H, 6.23, N, 7.17.

EXAMPLE A9 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 4-trifluoromethyl-benzylamide

IR (neat cm⁻¹) 3343, 2931, 1543, 1530, 1454, 1326, 1122; ¹HNMR (DMSO-d₆) δ 9.38 (s, 1H), 8.57 (t, J=5.0, 1H), 8.15 (d, J=8.4, 1H), 7.59 (d, J=8.2,2H), 7.50 (d, J=8.2,2H), 7.28-7.13 (m, 5H), 6.93 (t, J=7.5, 1H), 6.77 (d, J=7.7, 1H), 6.54 (d, J=7.3, 1H), 5.50 (s br, 1H), 5.15 (d, J=9.2, 1H), 5.02 (d, J=9.2, 1H), 4.47-4.21 (m, 5H), 2.85-2.67 (m, 2H), 1.81 (s, 3H), 1.51 (s, 3H), 1.34 (s, 3H); ); HRMS (ESI) m/z calcd for C₃₂H₃₄F₃N₃O₅SNa (M+Na)⁺ 652.2063, found 652.2044; Anal. Calcd for C₃₂H₃₄F 3N₃O₅S.0.25H₂O: C, 60.60; H, 5.48; N, 6.63. Found: C, 60.50; H, 5.29; N, 6.48.

EXAMPLE A10 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (2-oxo-2-phenyl-ethyl)-amide

¹HNMR (DMSO-d₆) δ 9.39 (s, 1H), 8.36 (t, J=4.8, 1H), 8.15 (d, J=8.1, 1H), 7.98 (d, J=7.4, 1H), 7.65 (m, 1H), 7.52 (m, 2H), 7.32-7.11 (m, 6H), 6.93 (t, J=7.9, 1H), 6.76 (d, J=7.9, 1H), 6.54 (d, J=7.5, 1H), 5.42 (d, J=6.4, 1H), 5.08 (d, J=9.3, 1H), 5.02 (d, J=9.0, 1H), 4.78-4.30 (m, 5H), 2.84-2.66 (m, 2H), 1.81 (s, 3H), 1.57 (s, 3H), 1.45 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₅N₃O₆SNa (M+Na)⁺ 612.2139, found 612.2141.

EXAMPLE A11 3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl-amino}-4-phenyl-butanoyl-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-fluoro-4-trifluoromethyl-benzylamide

¹H NMR (DMSO-d₆) δ 9.34 (s, 1H), 8.62 (t, J=5.9, 1H), 8.09-6.54 (m, 11H), 5.45 (s br, 1H), 5.18 (d, J=9.2, 1H), 5.03 (d, J=9.2, 1H), 4.55-4.00 (m, 5H), 4.45 (s, 1H), 2.86-2.49 (m, 2H), 1.82 (s, 3H), 1.53 (s, 3H), 1.36 (s, 3H); Anal. Calcd for C₃₂H₃₃N₃O₅SF₄: C, 59.34; H, 5.14; N, 6.49; S, 4.95. Found: C, 59.14; H, 5.29; N, 6.21; S, 4.67.

EXAMPLE A12 3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methyanoyl-amino}-4-phenyl-butanoyl)-5,5-dimehtyl-thiazolidine-4-carboxylic acid-2-trifluoromethyl-4-fluoro-benzylamide

¹H NMR (DMSO-d₆) δ 9.33 (s, 1H), 8.65 (t, J=5.9, 1H), 8.12-6.54 (m, 11H), 5.45 (d, J=6.9, 1H), 5.18 (d, J=9.2, 1H), 5.05 (d, J=9.2, 1H), 4.59-4.34 (m, 5H), 4.50 (s, 1H), 2.85-2.67 (m, 2H), 1.82 (s, 3H), 1.53 (s, 3H), 1.37 (s, 3H); Anal. Calcd for C₃₂H₃₃N₃O₅SF₄: C, 59.34; H, 5.14; N, 6.49; S, 4.95. Found: C, 59.26; H, 5.35; N, 6.23; S, 4.69.

EXAMPLE A13 3-[2-Hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl-5,5-dimethyl-thiazolidine-4-carboxylic acid 4-methanesulfonyl-benzamide

¹H NMR (DMSO-d₆) δ 9.38 (s, 1H), 8.37 (t, J=5.5, 1H,), 8.12 (d, 1H, J=8.2, 1H,), 7.33-7.13 (m, 7H), 6.94 (t, 1H, J=7.7, 1H,), 6.84-6.79 (m, 3H), 6.54 (d, 1H, J=7.3, 1H), 5.48 (d, J=6.6, 1H), 5.12 (d, J=9.2, 1H,), 5.00 (d, 1H, J=9.2, 1H), 4.49-4.42 (m, 3H), 4.32 (dd, J=14.8, 6.2, 1H,), 4.09 (dd, 1H, J=14.8, 5.3, 1H), 3.47 (s, 3H), 2.87-2.68 (m, 2H), 1.82 (s, 3H), 1.48 (s, 3H), 1.32 (s, 3H); Anal. Calcd for C₃₂H₃₇N₃O₇S₂: C, 60.07; H, 5.83; N, 6.57. Found C, 60.25; H, 6.13; N, 6.74.

EXAMPLE A14 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid allylamide

IR (neat cm⁻¹) 3342, 2966, 1637, 1531, 1460, 1366, 1284, 1108; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.13-8.07 (m, 2H), 7.34-7.13 (m, 5H), 6.93 (t, J=7.9, 1H), 6.78 (d, J=7.7, 1H), 6.53 (d, J=7.0, 1H), 5.82-5.70 (m. I H), 5.46 (d, J=6.6, 1H), 5.23-4.97 (m, 4H), 4.40 (m, 3H), 3.81-3.59 (m, 2H), 2.86-2.67 (m, 2H), 1.81 (s, 3H), 1.50 (s, 3H), 1.35 (s, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₃N₃O₅S Na (M+Na)⁺ 534.2039, found 534.2062; Anal. Calcd for C₂₇H₃₃N₃O₅S: C, 63.38; H, 6.50; N, 8.21. Found: C, 63.68; H, 6.57; N, 8.29.

EXAMPLE A15 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 4-dimethylamino-benzylamide

IR (neat cm⁻¹) 3331, 2931, 1643, 1519, 1455, 1349, 1284; ¹HNMR (DMSO-d₆) δ69.37 (s, 1H), 8.26 (m, 1H), 8.12 (d, J=7.1, 1H), 7.38-6.92 (m, 8H), 6.78 (t, J=7.9, 1H), 6.60 (d, J=8.6, 1H), 6.55 (d, J=7.3, 1H), 6.42 (d, J=8.2, 1H), 5.46 (d, J=6.0, 1H), 5.11 (d, J=9.3, 1H), 5.00 (d, J=9.3, 1H), 4.45 (m, 3H), 4.25 (m, 1H), 4.03 (m, 1H), 2.80 (s, 3H), 2.87-2.73 (m, 2H), 1.82 (s, 3H), 1.48 (s, 3H), 1.32 (s, 3H); HRMS (ESI) m/z calcd for C₃₃H₄₀N₄O₅SNa (M+Na)⁺ 627.2612, found 627.2607.

EXAMPLE A16 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 4-amino-benzylamide

Pale yellow solid: mp=107-109° C.; IR (cm⁻¹) 3378, 2919, 1631, 1518, 1453, 1382, 1281, 1121; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.21 (t, J=6.0, 1H), 7.40-7.10 (m, 6H), 8.12 (d, J=8.1, 1H), 6.92 (d, J=8.4, 2H), 6.77 (d, J=7.2, 1H), 6.54 (d, J=7.2, 1H), 6.44 (d, J=8.4, 2H), 5.44 (d, J=6.0, 1H), 5.10 (d, J=9.2, 1H), 4.99 (d, J=9.2, 1H), 4.90 (s, 2H), 4.50-4.32 (m, 3H), 4.22-3.93 (m, 2H), 2.90-2.60 (m, 2H), 1.81 (s, 3H), 1.47 (s, 3H), 1.31 (s, 3H); Anal. Calcd for C₃₁H₃₆N₄O₅S.0.25H₂O: C, 64.06; H, 6.33; N, 9.64. Found: C, 64.17; H, 6.38; N, 9.60.

EXAMPLE A17 3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid prop-2-ynylamide

¹H NMR (DMSO-d₆) δ 9.33 (s, 1H), 8.38 (t, J=5.5, 1H), 8.08 (d, J=8.3, 1H), 7.35-6.53 (m, 8H), 5.46 (d, J=6.6, 1H), 5.10 (d, J=9.2, 1H), 5.02 (d, J=9.2, 1H), 4.44-4.40 (m, 1H), 4.40 (s, 1H), 3.85 (m, 3H), 3.08 (t, J=2.5, 1H), 2.88-2.68 (m, 2H), 1.82 (s, 3H), 1.51 (s, 3H), 1.37 (s, 3H); Anal. Calcd for C₂₇H₃₁N₃O₅S: C, 63.63; H, 6.13; N, 8.24; S, 6.29. Found: C, 63.50; H, 6.33; N, 7.81; S, 5.68.

EXAMPLE A18 3-(2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoylamino}-4-phenyl-butanoyl)]-5,5-dimethyl-thiazolidine-4-carboxylic acid (2-methylsulfanyl-phenyl)-amide

¹H NMR (DMSO-d₆) δ 9.33 (s, 1H), 8.41 (t, J=5.7, 1H), 8.10 (d, J=8.3, 1H) 8.09-6.54 (m, 12H), 5.46 (d, J=6.6, 1H), 5.14 (d, J=9.2, 1H), 5.04 (d, J=9.2, 1H), 4.50-4.02 (m, 4H), 4.50 (s, 1H), 2.89-2.69 (m, 2H), 2.51 (s, 3H), 1.84 (s, 3H), 1.53 (s, 3H), 1.39 (s, 3H); Anal. Calcd for C₃₂H₃₇N₃O₅S₂: C, 63.24; H, 6.14; N, 6.91. Found: C, 63.01; H, 6.30; N, 6.53.

EXAMPLE A19 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid phenethyl-amide

¹H NMR (DMSO-d₆) δ 9.41 (s, 1H), 8.38(t, J=4.8, 1H), 8.16 (d, J=8.1, 1H), 8.01 (d, J=7.4, 1H), 7.64 (m, 1H), 7.52 (m, 2H), 7.32-7.11 (m, 6H), 6.93 (t, J=7.9, 1H), 6.76 (d, J=7.9, 1H), 6.54 (d, J=7.5, 1H), 5.42 (d, J=6.4, 1H), 5.10 (d, J=9.3, 1H), 5.05 (d, J=9.0, 1H), 4.80-4.32 (m, 5H), 2.84-2.66 (m, 4H), 1.80 (s, 3H), 1.56 (s, 3H), 1.45 (s, 3H); Anal. Calcd for C₃₂H₃₇N₃O₅S: C, 66.76; H, 6.48; N, 7.30. Found C, 66.50; H, 6.56; N, 7.23.

EXAMPLE A20 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid ((S)-1-phenyl-ethyl)-amide

White solid: mp=114-115° C.; IR (neat, cm⁻¹) 3306, 2971, 1643, 1531, 1451, 1372, 1284, 1211, 1107; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.45 (d, J=8.2, 1H), 8.19 (d, J=8.2, 1H), 7.32-7.18 (m, 10H), 6.96-6.91 (m, 1H), 6.76 (d, J=8.1, 1H), 6.54 (d, J=7.5, 1H), 5.36 (d, J=7.2, 1H), 5.08 (d, J=9.7, 1H), 5.01 (d, J=9.7, 1H), 4.95-4.85 (m, 2H), 4.48 (s, 1H), 4.45-4.30 (m, 1H), 2.80-2.60 (m, 2H), 1.79 (s, 3H), 1.47 (s, 3H), 1.36 (d, J=7.2, 3H), 1.30 (d, J=7.0, 3H); Anal. Calcd for C₃₂H₃₇N₃O₅S.0.25H₂O: C, 66.24; H, 6.51; N, 7.24. Found C, 66.30; H, 6.56; N, 6.89.

EXAMPLE A21 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid ((R)-1-phenyl-ethyl)-amide

White solid: mp=114-115° C.; IR (neat, cm⁻¹) 3299, 1643, 1583, 1520, 1454, 1377, 1284, 1104; ¹H NMR (DMSO-d₆) δ 9.35 (s, 1H), 8.36 (d, J=8.2, 1H), 8.15 (d, J=8.2, 1H), 7.44-7.13 (m, 10H), 6.96-6.91 (m, 1H), 6.75 (d, J=8.1, 1H), 6.52 (d, J=6.7, 1H), 5.38 (d, J=6.9, 1H), 5.15 (d, J=9.7, 1H), 4.99 (d, J=9.7, 1H), 5.28-4.74 (m, 1H), 4.52 (s, 1H), 4.49-4.35 (m, 2H), 2.80-2.60 (m, 2H), 1.79 (s, 3H), 1.50 (s, 3H), 1.38 (s, 3H), 1.34 (d, J=7.0, 3H); Anal. Calcd for C₃₂H₃₇N₃O₅S.0.25H₂O: C, 66.24; H, 6.51; N, 7.24. Found: C, 66.38; H, 6.52; N, 7.30.

EXAMPLE A22 3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (benzo[1,3]dioxol-5-ylmethyl)-amide

IR (neat or KBr cm⁻¹) 3302, 2922, 2351, 2333, 1768, 1750, 1646, 1537; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.44 (s, 1H), 8.13 (d, J=7.9 1H), 7.34-7.13 (m, 5H), 6.99-6.77 (m, 4H), 6.78 (d, J=7.7, 1H), 5.93 (d, J=7.1, 2H), 5.15 (d, J=7.0, 1H), 5.08 (d, J=7.8, 1H), 4.43 (d, J=9.32, 2H), 4.34 (m, 2H), 4.12 (d, J=6.18, 1H), 4.08 (d, J=6.08, 1H, 2.86-2.67 (m, 2H), 2.55 (s, 1H), 1.81 (s, 3H), 1.51 (s, 3H), 1.39 (s, 3H); Anal. Calcd C₃₂H₃₁N₃O₇S.0.65 TFA.1.0H₂O: C, 57.31 H, 5.44 N, 6.02. Found: C, 57.58 H, 5.47 N, 5.85.

EXAMPLE A23 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid allyl-methyl-amide

IR (neat, cm⁻¹) 3380, 2943, 1637, 1460, 1284, ¹HNMR (DMSO-d₆) δ 9.37 (s, 1H), 8.24 (d, J=8.4, 1H), 7.34-7.15 (m, 5H), 6.94 (t, J=7.5, 1H), 6.77 (d, J=7.7, 1H), 6.53 (d, J=7.5, 1H), 5.99 (m, 1H), 5.70-5.65 (m, 1H), 5.49-5.00 (m, 5H), 4.30-3.85 (m, 4H), 3.08 (s, 3H), 2.78-2.65 (m, 2H), 1.80 (s, 3H), 1.58 (s, 3H), 1.38 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₅N₃O₅SNa (M+Na)⁺ 548.2190, found 548.2178.

EXAMPLE A24 (R)-3-(2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid fluoro-trifluoromethyl-benzylamide

¹H NMR (DMSO-d₆) δ 9.34 (s, 1H), 8.32 (t, J=6.0, 1H, 8.20 (d, J=8.4, 1H), 7.70-7.56 (m, 3H), 7.37 (d, J=6.9, 2H), 7.27 (t, J=7.5, 2H), 7.18 (t, J=7.4, 1H), 6.97 (t, J=7.0, 1H), 6.79 (d, J=7.0, 1H), 6.58 (d, J=6.6, 1H), 5.15 (d, J=9.0, 1H), 5.02 (d, J=9.0, 1H), 4.60-4.48 (m, 3H), 4.48-4.32 (m, 2H), 2.88-2.65 (m, 2H), 1.83 (s, 3H), 1.48 (s, 3H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₃N₃O₅SF₄Na (M+Na)⁺ 670.1969, found 670.1999; Anal. Calcd for C₃₂H₃₃N₃O₅S F₄.1H₂O, 0.3 TFA: C, 55.94; H, 5.08; N, 6.00. Found: C, 55.74; H, 4.98; N, 5.94.

EXAMPLE A25 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-trifluoromethoxy-benzylamide

White solid: mp=102-105° C.; IR (cm⁻¹) 3306, 2966, 1644, 1586, 1520, 1216, 1166; ¹H NMR (DMSO-d₆) δ 9.38 (s, 1H), 8.53 (t, J=6.0, 1H), 8.12 (d, J=8.1, 1H), 7.40-7.13 (m, 9H), 6.96-6.91 (m, 1H), 6.77 (d, J=8.2, 1H), 6.54 (d, J=7.7, 1H), 5.48 (d, J=6.4, 1H), 5.13 (d, J=9.2, 1H), 5.00 (d, J=9.2, 1H), 4.46-3.97 (m, 5H), 2.87-2.67 (m, 2H), 1.81 (s, 3H), 1.50 (s, 3H), 1.30 (s, 3H); Anal. Calcd for C₃₂H₃₄F₃N₃O₆S.0.25H₂O: C, 59.11; H, 5.35; N, 6.46. Found: C, 58.91; H, 5.40; N, 6.30.

EXAMPLE A26 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-ethoxy-benzylamide

White solid: mp=105-107° C.; IR (cm⁻¹) 3322, 3063, 2978, 1643, 1585, 1538, 1454, 1354, 1265, 1159, 1050; ¹H NMR (DMSO-d₆) δ 9.38 (s, 1H), 8.40 (t, J=5.6, 1H), 8.11 (d, J=8.2, 1H), 7.30-6.70 (m, 1H), 6.53 (d, J=7.5, 1H), 5.48 (d, J=5.9, 1H), 5.11 (d, J=8.9, 1H), 5.00 (d, J=8.9, 1H), 4.50-4.20 (m, 4H), 4.07 (dd, J=15.0, 5.3, 1H), 3.94 (dd, J=14.0, 6.9, 2H), 2.90-2.62 (m, 2H), 1.81 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H), 1.25 (t, J=6.9, 3H); Anal. Calcd for C₃₃H₃₉N₃O₆S.0.75H₂O: C, 64.01; H, 6.59; N, 6.79. Found: C, 63.89; H, 6.27; N, 6.44.

EXAMPLE A27 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid methyl-prop-2-ynyl-amide

IR (neat, cm⁻¹) 3378, 1643, 1461, 1279,1108, ¹H NMR (DMSO-d₆) δ 9.37 (s, 1H), 8.21 (d, J=9.2, 1H), 7.33-7.13 (m, 5H), 6.94 (t, J=7.7, 1H), 6.78 (d, J=8.1, 1H), 6.52 (d, J=7.0, 1H), 5.45 (d, J=6.8, 1H), 5.16 (d, J=9.2, 1H), 5.02 (d, J=9.2, 1H), 4.98 (s, 1H), 4.47-4.13 (s, 3H), 4.03-3.92 (m, 1H), 3.17 (s, 3H), 2.88 (s, 1H), 2.79-2.50 (m, 2H), 1.80 (s, 3H), 1.57 (s, 3H), 1.36 (s, 3H); Anal. Calcd for C₂₈H₃₃N₃O₅S.0.6H₂O: C, 62.95; H, 6.45; N, 7.86. Found: C, 62.95; H, 6.39; N, 7.69.

EXAMPLE A28 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl]methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (2-methyl-allyl)-amide

¹H NMR (DMSO-d₆) δ 9.33, (s, 1H), 8.18-7.79 (m, 2H), 7.39-7.12 (m, 5H), 6.92 (t, J=8.1, 1H), 6.75 (d, J=8.1, 1H), 6.53 (d, J=7.0, 1H), 5.09 (d, J=9.2, 1H), 4.96 (d, J=9.2, 1H), 4.70 (s, 1H), 4.43 (s, 1H), 4.40 (br s, 2H) 3.81-3.49 (m, 4H), 2.85-2.65 (m, 2H), 1.82 (s, 3H), 1.63 (s, 3H), 1.49 (s, 3H), 1.35 (s, 3H); Anal. Calcd for C₂₈H₃₅N₃O₅S: C, 63.97; H, 6.71; N, 7.99. Found: C, 63.85; H, 6.92; N, 7.65.

EXAMPLE A29 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-amino-benzylamide

IR (neat, cm⁻¹) 3401, 2943, 1643, 1525, 1461, 1373; ¹HNMR (DMSO-d₆) δ9.36 (s, 1H), 8.28 (t, J=8.0, 1H), 8.12 (d, J=8.9, 1H), 7.33-6.37 (m, 12H), 5.45 (d, J=7.0, 1H), 5.10 (d, J=8.9, 1H), 4.99 (d, J=8.9, 1H), 4.50-4.35 (m, 3H), 4.30-3.90 (m 2H), 2.90-2.70 (m, 2H), 2.06 (s, 2H), 1.81 (s, 3H), 1.48 (s, 3H), 1.33 (s, 3H); Anal. Calcd for C₃₁H₃₆N₄O₅S.0.5H₂O: C, 63.57; H, 6.37; N, 9.57. Found: C, 63.59; H, 6.38; N, 9.58.

EXAMPLE A30 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid cyanomethylamide

¹HNMR (DMSO-d₆) δ 9.34 (s, 1H), 8.65 (s, 1H), 8.15 (m, 1H), 7.42-7.19 (m, 5H), 6.94 (t, J=7.9, 1H), 6.81 (d, J=7.9, 1H), 6.62 (d, J=7.9,1H), 5.22 (d, J=9.7, 1H), 5.05 (d, J=9.7, 1H), 4.61-4.36 (m, 4H), 3.01-2.71 (m, 4H), 1.84 (s, 3H), 1.47 (s, 3H), 1.34 (s, 3H); Anal. Calcd for C₂₆H₃₀N₄O₅S: C, 61.16; H, 5.92; N, 10.97. Found: C, 61.24; H, 6.14; N, 10.62.

EXAMPLE A31 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (Z)-but-2-enylamide

¹HNMR (DMSO-d₆) δ 9.37 (s, 1H), 8.35 (m, 1H), 8.12 (m, 1H), 7.15-6.98 (m, 6H), 6.77 (d, J=7.7, 1H), 6.68 (d, J=7.5, 1H), 5.60-5.33 (m, 3H), 5.18 (d, J=9.2, 1H), 5.02 (d, J=9.2, 1H), 4.52-4.39 (m, 3H), 3.79-3.68 (m, 2H), 2.92-2.62 (m, 2H), 1.80 (s, 3H), 1.61 (d, J=6.9, 3H), 1.51 (s, 3H), 1.38 (s, 3H); Anal. Calcd for C₂₈H₃₅N₃O₅S: C, 63.97; H, 6.71; N, 7.99. Found: C, 63.73; H, 6.75; N, 7.83.

EXAMPLE A32 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (3-methyl-but-2-enyl)-amide

¹H NMR (DMSO-d₆) δ 9.33 (s, 1H), 8.19 (d, J=8.6, 1H), 7.96 (s br, 1H), 7.39-7.18 (m, 5H), 6.91 (t, J=7.6, 1H), 6.79 (d, J=7.9, 1H), 6.55 (d, J=7.1, 1H), 5.41 (m br, 1H), 5.21 (m, 2H), 5.02 (d, J=9.1, 1H), 4.57-4.37 (m, 3H), 3.79-3.61 (m, 2H), 2.90-2.71 (m, 2H), 1.81 (s, 3H), 1.63 (s, 6H), 1.52 (s, 3H), 1.40 (s, 3H); Anal. Calcd for C₂₉H₃₇N₃O₅S: C, 64.54; H, 6.91; N, 7.79. Found: C, 64.75; H, 6.82; N, 7.43.

EXAMPLE A33 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-acetylamino-benzylamide

White solid: mp=145-147° C.; IR (neat, cm⁻¹) 3378, 2919, 1637, 1514, 1461, 1361; ¹H NMR (DMSO-d₆) δ 9.87 (s, 1H), 9.36 (s, 1H), 8.45-8.40 (m, 1H), 8.12 (d, J=7.9, 1H), 7.49-6.91 (m, 10H), 6.77 (d, J=7.9, 1H), 6.55 (d, J=7.9, 1H), 5.49 (d, J=7.0, 1H), 5.10 (d, J=9.3, 1H), 5.00 (d, J=9.3, 1H), 4.44-3.95 (m, 5H), 2.90-2.62 (m, 2H), 2.00 (s, 3H), 1.80 (s, 3H), 1.48 (s, 3H), 1.32 (s, 3H); Anal. Calcd for C₃₂H₃₈N₄O₆S.1.5H₂O: C, 61.38; H, 6.40; N, 8.68. Found: C, 61.49; H, 6.14; N, 8.35.

EXAMPLE A34 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid ((Z)-2-methyl-but-2-enyl)-amide

¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.16 (d, J=8.4, 1H), 8.00 (t, J=5.3, 1H), 7.36-7.13 (m, 5H), 6.94 (t, J=7.7, 1H), 6.77 (d, J=8.1, 1H), 6.53 (d, J=7.3, 1H), 5.37 (d, J=5.7, 1H), 5.24 (m, 1H), 5.12 (d, J=9.0, 1H), 5.00 (d, J=9.0, 1H), 4.48-4.39 (m, 3H), 3.71 (d, J=3.7, 2H), 2.82-2.65 (m, 2H), 1.80 (s, 3H), 1.61 (m, 6H), 1.49 (s, 3H), 1.35 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₇N₃O₅SNa (M+Na)⁺ 562.2346, found 562.2360; Anal. Calcd for C₂₉H₃₇N₃O₅S: C, 64.54; H, 6.91; N, 7.79. Found: C, 64.33; H, 6.92; N, 7.60.

EXAMPLE A35 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid ((E)-2-methyl-but-2-enyl)-amide

¹HNMR (DMSO-d₆) δ 9.37 (s, 1H), 8.11 (d, J=8.2, 1H), 7.96(t, J=5.5, 1H), 7.34-7.13 (m, 5H), 6.94 (t, J=7.7, 1H), 6.77 (d, J=8.1, 1H), 6.53 (d, J=7.3, 1H), 5.44 (d, J=6.6, 1H), 5.34 (d, J=6.6, 1H), 5.10 (d, J=9.0, 1H), 4.98 (d, J=9.1, 1H), 4.47-4.36 (m, 3H), 3.71 (dd, J=14.7, 6.6, 1H), 3.46 (dd, J=14.5, 4.8, 1H), 2.85-2.67 (m, 2H), 1.81 (s, 3H), 1.50 (m, 9H), 1.35 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₇N₃O₅SNa (M+Na)⁺ 562.2346, found 562.2220.

EXAMPLE A36 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (E)-pent-2-enylamide

White solid: mp=113-115° C.; IR (neat, cm⁻¹) 3315, 2964, 1643, 1584, 1530, 1454, 1371, 1283, 1104, 969; ¹HNMR (DMSO-d₆) δ9.35 (s, 1H), 8.11 (d, J=8.2,1H), 8.02 (t, J=5.6, 1H), 7.33-7.13 (m, 5H), 6.96-6.90 (m, 1H), 6.76 (d, J=8.2, 1H), 6.52 (d, J=7.5, 1H), 5.66-5.56 (m, 1H), 5.43 (d, J=6.8, 1H), 5.38-5.31 (m, 1H), 5.10 (d, J=8.9, 1H), 4.99 (d, J=8.9, 1H), 4.47-4.39 (m, 2H), 4.38 (s, 1H), 3.72-3.53 (m, 2H), 2.84-2.66 (m, 2H), 1.98-1.83 (m, 2H), 1.80 (s, 3H), 1.48 (s, 3H), 1.34 (s, 3H), 0.87 (t, J=7.3, 3H); Anal. Calcd for C₂₉H₃₇N₃O₅S.0 5H₂O: C, 63.48; H, 6.98; N, 7.66. Found: C, 63.30; H, 7.00; N, 7.28.

EXAMPLE A37 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (Z)-pent-2-enylamide

White solid: mp=112-113° C.; IR (neat, cm⁻¹) 3320, 2965, 1659, 1643, 1538, 1455, 1372, 1285, 1210, 1105, 1048; ¹H NMR (DMSO-d₆) δ 9.35 (s, 1H), 8.11 (d, J=7.9, 1H), 8.03 (t, J=5.3, 1H), 7.35-7.13 (m, 5H), 6.96-6.90 (m, 1H), 6.76 (d, J=8.1, 1H), 6.53 (d, J=7.3, 1H), 5.42 (d, J=6.7, 1H), 5.37-5.35 (m, 1H), 5.29-5.23 (m, 1H), 5.09 (d, J=9.2, 1H), 4.99 (d, J=9.2, 1H), 4.45-4.38 (m, 2H), 4.36 (s, 1H), 3.80-3.62 (m, 2H), 2.84-2.70 (m, 2H), 2.07-1.97 (m, 2H), 1.80 (s, 3H), 1.48 (s, 3H), 1.34 (s, 3H), 0.90 (t, J=7.5, 3H); Anal. Calcd for C₂₉H₃₇N₃O₅S.0 5H₂O: C, 63.48; H, 6.98; N, 7.66. Found: C, 63.60; H, 6.92; N, 7.48.

EXAMPLE A38 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (E)-but-2-enylamide

¹H NMR (DMSO-d₆) δ 9.39 (s, 1H), 8.19 (m br, 1H), 8.03 (m br, 1H), 7.40-7.16 (m, 5H), 6.94 (t, J=7.1, 1H), 6.79 (d, J=7.7, 1H), 6.55 (d, J=7.5, 1H), 5.64-5.31 (m, 3H), 5.19 (d, J=9.2, 1H), 5.02 (d, J=9.2, 1H), 4.55-4.38 (m, 3H), 3.80-3.69 (m, 2H), 2.84-2.70 (m, 2H), 1.80 (s, 3H), 1.61 (s br, 3H), 1.51 (s, 3H), 1.39 (s, 3H); Anal. Calcd for C₂₈H₃₅N₃O₅S: C, 63.73; H, 7.07; N, 7.96. Found: C, 63.41; H, 7.23; N, 7.71.

EXAMPLE A39 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-dimethylamino-benzylamide

White solid: mp=105-106° C.; IR (neat, cm⁻¹) 2219, 2966, 1732, 1644, 1585, 1531, 1494, 1454, 1373, 1264, 1047; ¹H NMR (DMSO-d₆) δ 9.37 (s, 1H), 8.33 (t, J=6.1, 1H), 8.08 (d, J=8.1, 1H), 7.32-6.52 (m, 12H), 5.54 (d, J=6.0, 1H), 5.10 (d, J=9.2, 1H), 4.99 (d, J=9.2, 1H), 4.43-4.31 (m, 4H), 4.03 (dd, J=15.3, 5.3, 1H), 2.84 (s, 6H), 2.84-2.67 (m, 2H), 1.81 (s, 3H), 1.49 (s, 3H), 1.35 (s, 3H). Anal. Calcd for C₃₃H₄₀N₄O₅S.0.1H₂O: C, 65.35; H, 6.68; N, 9.24. Found: C, 65.49; H, 6.67; N, 9.30.

EXAMPLE A40 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid ((E)-4,4,4-trifluoro-but-2-enyl)-amide

White foam; IR (neat, cm⁻¹) 3332, 1661, 1641, 1584, 1531, 1443, 1280, 1119; ¹HNMR (DMSO-d₆) δ 9.36 (s, 1H), 8.32 (t, J=5.6, 1H), 8.15 (d, J=8.4, 1H), 7.35-7.12 (m, 5H), 7.00-6.90 (m, 1H), 6.77 (d, J=7.3, 1H), 6.52 (d, J=7.3, 1H), 6.49-6.40 (m, 1H), 6.08-6.00 (m, 1H), 5.49 (d, J=6.4, 1H), 5.15 (d, J=9.2, 1H), 5.01 (d, J=9.2, 1H), 4.50-4.40 (m, 2H), 4.38 (s, 1H), 4.10-3.90 (m, 1H), 3.80-3.70 (m, 1H), 2.90-2.60 (m, 2H), 1.80 (s, 3H), 1.51 (s, 3H), 1.34 (s, 3H); Anal. Calcd for C₂₈H₃₂F₃N₃O₅S: C, 58.02; H, 5.56; N, 7.25. Found: C, 58.37; H, 5.70; N, 6.91.

EXAMPLE A41 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (1-cyano-1,1-dimethyl-methyl)-amide

¹H NMR (DMSO-d₆) δ 9.39 (s, 1H), 8.31-8.12 (m, 2H), 7.38-7.17 (m, 5H), 6.97 (t, J=7.3, 1H), 6.79 (d, J=7.7, 1H), 6.59 (d, J=7.4, 1H), 5.41 (m br, 1H), 5.21 (d, J=9.2, 1H), 5.00 (d, J=9.2, 1H), 4.58-4.35 (m, 3H), 2.85-2.62 (m, 2H), 1.81 (s, 3H), 1.62 (s, 6H), 1.47 (s, 3H), 1.39 (s, 3H); Anal. Calcd for C₂₈H₃₄N₄O₅S: C, 62.43; H, 6.36; N, 10.40. Found: C, 62.12; H, 6.55; N, 10.13.

EXAMPLE A42 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-hydroxy-benzylamide

¹H NMR (DMSO-d₆) δ 9.37 (s, 1H), 9.30 (s, 1H), 8.35 (t, J=5.9, 1H), 8.11 (d, J=8.1, 1H), 7.33-7.15 (m, 5H), 7.04 (t, J=7.7, 1H), 6.94 (t, J=7.9, 1H), 6.77 (d, J=8.1, 1H), 6.70-6.54 (m, 4H), 5.49 (s br, 1H), 5.11 (d, J=9.2, 1H), 5.00 (d, J=9.3, 1H), 4.43 (m, 3H), 4.27 (dd, J=15.2, 6.0, 1H), 4.07 (dd, J=15.0, 5.5, 1H), 2.88-2.67 (m, 2H), 1.82 (s, 3H), 1.49 (s, 3H), 1.33 (s, 3H); Anal. Calcd for C₃₁H₃₅N₃O₆S.H₂O: C, 62.50; H, 6.26; N, 7.05. Found: C, 62.66; H, 6.19; N, 6.83.

EXAMPLE A43 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-propoxy-benzylamide

White foam; IR (cm⁻¹) 3319, 2966, 1644, 1585, 1531, 1454, 1373, 1264, 1047; ¹H NMR (DMSO-d₆) δ 9.37 (s, 1H), 8.40 (t, J=5.8, 1H), 8.10 (d, J=8.4, 1H), 7.31-6.71 (m, 1H), 6.53 (d, J=7.3, 1H), 5.46 (d, J=6.4, 1H), 5.12 (d, J=9.2, 1H), 5.00 (d, J=9.2, 1H), 4.50-4.20 (m, 4H), 4.11-3.83 (m, 3H), 2.90-2.62 (m, 2H), 1.81 (s, 3H), 1.72-1.60 (m, 2H), 1.49 (s, 3H), 1.34 (s, 3H), 0.92 (t, J=7.3, 3H). Anal. Calcd for C₃₄H₄₁N₃O₆S.0.25H₂O: C, 65.42; H, 6.70; N, 6.73. Found: C, 65.49; H, 6.67; N, 6.70.

EXAMPLE A44 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-hydroxy-benzylamide

¹H NMR (DMSO-d₆) δ 9.50 (s, 1H), 9.36 (s, 1H), 8.33 (t, J=5.5, 1H), 8.14 (d, J=8.2, 1H), 7.32-7.12 (m, 6H), 7.04-6.91 (m, 2H), 6.76 (m, 2H), 6.68 (t, J=7.5, 1H), 6.54 (d, J=7.5, 1H), 5.46 (d, J=6.6, 1H), 5.13 (d, J=9.2, 1H), 5.01 (d, J=9.3, 1H), 4.47 (m, 3H), 4.28-4.19 (m, 2H), 2.86-2.67 (m, 2H), 1.82 (s, 3H), 1.49 (s, 3H), 1.32 (s, 3H); HRMS (ESI) m/z calcd for C₃₁H₃₆N₃O₆S (M+H)⁺ 578.2325, found 578.2325.

EXAMPLE A45 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (3,3,3-trifluoro-propyl)-amide

¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.20 (t, J=5.5, 1H), 8.13 (d, J=8.2, 1H), 7.34-7.13 (m, 5H), 6.93 (t, J=7.7, 1H), 6.76 (d, J=8.1, 1H), 6.08 (d, J=7.5, 1H), 5.44 (d, J=6.8, 1H), 5.10 (d, J=9.2, 1H), 5.05 (d, J=9.2, 1H), 4.48-4.38 (m, 2H), 4.35 (s, 1H), 3.32-3.25 (m, 2H), 2.75-2.70 (m, 2H), 2.44-2.35 (m, 2H), 1.80 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₃N₃O₅SF₃ (M+H)⁺ 568.2093, found 568.2118.

EXAMPLE A46 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid methyl-propyl-amide

White solid: mp=108-110° C.; IR (cm⁻¹) 3325, 2964, 1637, 1522, 1456, 1372, 1284; ¹H NMR (DMSO-d₆) δ 9.35 (s, 1H), 8.22 (d, J=8.6, 1H), 7.34-7.12 (m, 5H), 6.96-6.90 (m, 1H), 6.77-6.75 (m, 1H), 6.53-6.50 (m, 1H), 5.46 (d, J=6.4, 1H), 5.18-4.70 (m, 3H), 4.48-4.20 (m, 2H), 3.31 (s, 3H), 2.90-2.50 (m, 2H), 1.80 (s, 3H), 1.80-1.77 (m, 2H), 1.56 (s, 3H), 1.56-1.36 (m, 2H), 1.37 (s, 3H), 0.79 (t, J=7.5, 3H). Anal. Calcd for C₂₈H₃₇N₃O₅S.1.0H₂O: C, 61.63; H, 7.20; N, 7.60. Found: C, 62.03; H, 6.93; N, 7.33.

EXAMPLE A47 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 4-trifluoromethoxy-benzylamide

White solid: ¹H NMR (DMSO) δ 9.37 (s, 1H), 8.51 (t, J=5.9, 1H), 8.13 (d, J=7.3, 1H), 7.39 (d, J=8.6, 1H), 7.32-7.10 (m, 8H), 7.00-6.90 (m, 1H), 6.76 (d, J=8.2, 1H), 6.53 (d, J=7.3, 1H), 5.49 (d, J=6.6, 1H), 5.14 (d, J=9.3, 1H), 5.00 (d, J=9.3, 1H), 4.49-4.37 (m, 4H), 4.17 (dd, J=15.0, 5.7, 1H), 2.90-2.64 (m, 2H), 1.81 (s, 3H), 1.49 (s, 3H), 1.32 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₅N₃O₆F₃S (M+H)⁺ 646.2199, found 646.2184.

EXAMPLE A48 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (2,2-difluoro-benzo[1,3]dioxol-5-ylmethyl)-amide

¹HNMR (DMSO-d₆) δ9.36 (s, 1H), 8.55 (t, J=5.8, 1H), 8.14 (d, J=8.4, 1H), 7.29-7.11 (m, 8H), 6.94 (t, J=7.8, 1H), 6.77 (d, J=7.9, 1H), 6.54 (d, J=7.4, 1H), 5.58 (d, J=8.2, 1H), 5.17 (d, J=9.2, 1H), 5.02 (d, J=9.2, 1H), 4.49-4.39 (m, 3H), 4.43 (s, 1H), 4.21 (dd, J=5.4, 15.3, 1H), 2.83 (m, 1H), 2.71 (dd, J=13.5, 10.7, 1H), 2.20 (s, 3H), 1.51 (s, 3H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₄F₂N₃O₇S (M+H)⁺ 642.2086, found 642.2099; Anal. Calcd for C₃₂H₃₃F₂N₃O₇S: C, 59.90; H, 5.18; N, 6.55. Found: C, 60.01; H, 5.27; N, 6.29.

EXAMPLE A49 (R)-3-[(2S,3S)-2-Hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid (2-chloro-ethyl)-amide

¹HNMR (DMSO-d₆) δ 9.40 (s, 1H), 8.31 (t, 1H, J=5.5), 8.17 (d, 1H, J=8.4), 7.37-7.16 (m, 5H), 6.96 (t, 1H, J=7.9), 6.79 (d, 1H, J=8.1), 6.55 (d, 1H, J=7.5), 5.47 (d, 1H, J=6.8), 5.11 (d, 1H, J=9.3), 5.03 (d, 1H, J=9.3), 4.50-4.45 (m, 2H), 4.41 (s, 1H), 3.64-3.58 (m, 2H), 3.46-3.34 (m, 2H), 2.86-2.69 (m, 2H), 1.82 (s, 3H), 1.53 (s, 3H), 1.40 (s, 3H). Exact mass calculated for C₂₆H₃₃N₃O₅SCI (M+H)⁺ 534.1829, found 534.1841.

EXAMPLE A50 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (2-hydroxy-ethyl)-(2-methyl-benzyl)-amide

¹HNMR (DMSO-d₆) δ 9.38 (s, 1H), 8.29 (d, J=8.4, 1H), 7.42-6.87 (m, 10H), 6.78 (d, J=7.1, 1H), 6.55 (d, J=6.8, 1H), 5.44 (d, J=6.8, 1H), 5.26 (d, J=10.0, 1H), 5.08 (s, 1H), 5.04 (d, J=9.2, 1H), 4.82-4.67 (m, 2H), 4.55-4.24 (m, 3H), 3.67 (m, 2H), 3.47 (m, 2H), 2.78 (m, 2H), 2.24 (s, 3H), 1.82 (s, 3H), 1.61 (s, 3H), 1.45 (s, 3H); HRMS (ESI) m/z calcd for C₃₄H₄₂N₃O₆S (M+H)⁺ 620.2794, found 620.2798; Anal. Calcd for C₃₄H₄₁N₃O₆S I H₂O: C, 64.03; H, 6.80; N, 6.59. Found: C, 63.66; H, 6.40; N, 6.59.

EXAMPLE A51 3-[2-Hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiiazolidine-4-carboxylic acid methyl-(2-ethyl-benzyl)-amide

White solid: ¹H NMR (DMSO-d₆) δ 9.40 (s, 1H), 8.45 (t, J=7.99, 1H), 8.10 (d, J=8.1, 1H), 7.41-6.91 (m, 12H), 6.62 (d, J=7.8, 1H), 5.41 (d, J=6.8, 1H), 5.12 (dd, J=8.1, 7.8, 1H), 4.44-4.35 (m, 3H), 4.42 (s, 1H), 2.91-2.67 (m, 2H), 2.54-2.21 (q, J=6.89, 2H), 2.1 (s, 3H), 1.88 (s, 3H), 1.56 (t, J=6.90, 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₃₄H₄₁N₃O₅S.0.75H₂O) calculated C (62.34), H (6.43), N (6.23), found C (62.72), H (6.52), N (5.97). HRMS (ESI) m/z calcd for 604.2845, found 604.2845.

EXAMPLE A52 3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid (2-methylamino-ethyl)-amide

White solid: ¹H NMR (DMSO-d₆) δ 9.40 (s, 1H), 8.45-8.01 (m, 1H), 7.41-7.13 (m, 12H), 6.98 (t, J=7.8, 1H), 6.78 (d, J=6.85, 1H), 6.55 (d, J=6.99, 1H), 5.41 (m, 1H), 5.12-4.98 (m, 2H), 4.44-4.35 (m, 2H), 3.15 (m, 2H), 2.91-2.67 (m, 2H), 1.84 (s, 3H), 1.66 (q, J=8.2, 4H), 1.34 (s, 3H); Anal. (C₂₇H₃₆N₄O₅S.0.50H₂O) calculated C (60.31), H (6.94), N (10.42), found C (60.59), H (6.50), N (8.08). HRMS (ESI) m/z calcd for 556.2771, found 556.2770.

Amides of the general structure 3 (synthesized in the same manor as in the Methods A section) are coupled to boc-protected acid 15, and exposed to methane sulfonic acid to yield amines 16. Subjecting amines 16 to the reaction conditions depicted yielded a series of amides 17 and ureas 19.

Synthesis of amines of the general type 16.

The title compound was prepared as follows. (R)-5,5-Dimethyl-thiazolidine-3,4-dicarboxylic acid 3-tert-butyl ester 1 (1.95 g, 7.47 mmol) was dissolved in EtOAc (25 mL) and cooled to 0° C. Diphenyl chlorophosphate (1.71 mL, 8.23 mmol) was added followed by TEA (1.14 mL, 8.23 mmol). The reaction was stirred at 0° C. for 1 h, and treated with (S)-Cyclohex-2-enylamine (0.8 g, 8.23 mmol). The reaction mixture was stirred at room temperature overnight, then partitioned between 1N HCl (25 mL) and EtOAc (30 mL). The organic layer was washed with saturated NaHCO₃, brine, dried over Na₂SO₄ and concentrated to a yellow oil. The resulting oil (2.54 g, 7.47 mmol) was dissolved in EtOAc (30 mL) and then cooled to 0° C. Methanesulfonic acid (2.27 mL, 33.62 mmol) was added and the solution was stirred at 0° C. for 15 minutes, then at room temperature for 4 h. The mixture was re-cooled to 0° C. and quenched with 10% Na₂CO₃ (30 mL) then extracted with EtOAc (30 mL). Organic layer was washed with brine, dried over Na₂SO₄ and concentrated in vacuo to give a yellow oil 3. The resulting yellow oil (1.86 g, 7.74 mmol) was dissolved in EtOAc (77 mL). BOC-AHPBA 4 (2.29 g, 7.74 mmol) was added followed by HOBt (1.05 g, 7.74 mmol). The mixture was stirred at room temperature 1 h, then cooled to 0° C. DCC (1.60 g, 7.74 mmol) was slowly added as solution in EtOAc (30 mL). The mixture was allowed to gradually warm to room temperature and stirred overnight. The mixture was filtered and the filtrate was washed with 1N HCl (40 mL), saturated NaHCO₃ (40 mL), brine (40 mL), dried over Na₂SO₄ and concentrated to give a crude white solid (contaminated with DCU). The DCU was removed by flash chromatography (30% to 50% EtOAc in hexanes) to provide a white solid (4 g, 7.73 mmol), which was dissolved in EtOAc (30 mL) and then cooled to 0° C. Methanesulfonic acid (2.35 mL, 34.76 mmol) was added and the solution was stirred at 0° C. for 15 minutes, then at room temperature for 3 h. The mixture was re-cooled to 0° C. and quenched with 10% Na₂CO₃ (35 mL) then extracted with EtOAc (30 mL). Organic layer was washed with brine, dried over Na₂SO₄ and concentrated in vacuo to give a material which was recrystalized from 60% EtOAc in hexanes to provide the titled compound (2.41 g, 80%) as a white solid. ¹H NMR (DMSO-d₆) δ 8.21 (d, J=8.1, 1H), 7.31-7.17 (m, 5H), 5.80 (d, J=5.6, 1H), 5.52-5.48 (m, 2H), 5.30-5.25 (m, 2H), 4.89 (s, 2H), 4.26 (s, 1H), 4.21-4.00 (m, 3H), 3.15-2.70 (m, 2H), 2.50-2.00 (m, 2H), 2.00-1.00 (m, 4H), 1.49 (s, 3H), 1.31 (s, 3H); Anal. Calcd for C₂₂H₃₁N₃O₃S: C, 63.28; H, 7.48; N, 10.06. Found: C, 63.40; H, 7.20; N, 9.98. The Following Amines a-h were Prepared by the Specific Method Outlined above Using the Requisite Amine.

¹H NMR (DMSO-d₆) δ 8.36 (t, J=6.0,1H), 7.36-7.14 (m, 5H), 5.70 (m, 1H), 5.34 (s br, 1H), 5.12 (d, J=17.0, 1H), 496-4.88 (m, 3H), 4.34 (s, 1H), 4.10 (d, J=7.0, 1H), 3.80-3.55 (m, 2H), 3.06 (d, J=13.0, 1H), 2.87 (t, J=9.0, 1H), 2.38 (dd, J=13.0,10.0, 1H), 1.52 (s, 3H), 1.33 (s, 3H).

¹H NMR (DMSO-d₆) δ 8.69 (t, J=5.3,1H), 7.34-7.14 (m, 5H), 5.34 (s br, 1H), 4.90 (s, 2H), 4.29 (s, 1H), 4.08 (d, J=7.0, 1H), 3.90-3.70 (m, 2H), 3.07 (dd, J=13.4,2.5,1H), 2.96 (t, J=2.6,1H), 2.88, (ddd, J=9.8, 8.0, 2.8, 1H), 2.37 (dd, J=13.2, 9.9, 1H), 1.50 (s, 3H), 1.32 (s, 3H).

¹H NMR (DMSO-d) δ 8.13 (t, J=5.4, 1H), 7.35-7.15 (m, 5H), 5.28 (d, J=8.1, 1H), 4.79 (m, 2H), 4.27 (s, 1H), 4.07 (t, J=7.1, 1H), 3.10-2.71 (m, 4H), 2.37 (dd, J=13.2, 9.9, 1H), 1.49 (s, 3H), 1.34 (m, 2H), 1.33 (s, 3H), 0.77 (t, J=7.4, 3H).

Isolated yield: 84%; MS (APCI, m/z): 461, 463 (M+H)

Isolated yield: 93%; MS (APCI, m/z): 464 (M+H).

Isolated yield: 86%; MS (APCI, m/z): 496 (M+H).

Isolated yield: 87%. MS-APCI (m/z+): 458.

Synthesis of Final Products of the General Type 17 from 16a-h, General Methods:

Amide formation—To a solution of acid, amine 16 and HOBT in CH₂Cl₂ was added EDC and the solution stirred overnight at room temperature. The solution was concentrated in vacuo and the residue dissolved in ethyl acetate and a small portion of water. The solution was washed with saturated NH₄Cl or 0.5N HCl (2×), saturated NaHCO₃ (2×), brine (1×), dried with MgSO₄ and concentrated in vacuo. The resulting residue subjected to flash silica gel chromatography or preparative HPLC to afford the desired product.

Urea formation #1—The corresponding amine and isocyanate (1.1-1.2 eq.) were taken in dichloromethane and stirred at room temperature under nitrogen. (1.5 hr to overnight). The solvent was then removed in vacuo and the resulting residue subjected to flash silica gel chromatography or preparative HPLC to afford the desired product.

Urea formation #2—The corresponding amine was dissolved in CH₂Cl₂ and treated with diisopropylethylamine (1.5 eq.) and phosgene (1 eq., 20% soln. in toluene) at −78° C. The resulting solution was warmed to room temperature and treated with the amine of general structure 16. The resulting residue subjected to flash silica gel chromatography or preparative HPLC to afford the desired product.

Specific Urea Synthesis EXAMPLE B1 3-(2-hydroxy-3-{[1-(3-hydroxy-pyrrolidin-yl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid-2-methyl-benzylamide

(R)-Pyrrolidin-3-ol (0.21 g, 2.40 mmol) was dissolved in dry CH₂Cl₂ (15 mL) and cooled to −78° C. under argon with magnetic stirring. To this solution was added Diisopropylethylamine (0.63 mL, 3.63 mmol) followed by Phosgene as a 20% solution in toluene (1.2 mL, 2.40 mmol). The resulting yellow solution was stirred for 20 min at −78° C. then allowed to warm to room temperature. The solution was concentrated and re-dissolved in dry CH₂Cl₂ (5 mL) and THF (5 mL). To this was added Diisopropylethylamine (0.31 mL, 1.81 mmol) followed by 16c. The result was stirred for 16 h at 23° C. then diluted with EtOAc (50 mL). The mixture was washed sequentially with 10% citric acid (1×50 mL), saturated NaHCO₃ (1×50 mL), H₂O (1×50 mL). The organics were dried over Na₂SO₄, filtered, and concentrated. The residue was purified by flash column chromatography (5% MeOH in EtOAc) to yield the title compound (0.12 g, 18%) as a white foam.

¹H NMR (DMSO-d₆) δ 8.38 (t, J=5.7, 1H), 7.34-7.09 (m, 10H), 5.99 (d, J=8.3, 1H), 5.04 (d, J=9.5, 1H), 4.96 (d, J=9.5, 1H), 4.49 (s, 1H), 4.48-4.38 (m, 3H), 4.22-3.83 (m, 4H), 3.29-3.04 (m, 3H), 2.77-2.70 (m, 2H), 2.28 (s, 3H), 1.52 (s, 3H), 1.32 (s, 3H), 1.82-1.69 (m, 2H); HRMS (ESI) m/z calcd for C₂₉H₃₈N₄O₅SNa (M+Na)⁺ 577.2455, found 577.2440; Anal. Calcd for C₂₉H₃₈N₄O₅S.2H₂O: C, 58.96; H, 7.17; N, 9.48; S, 5.43. Found: C, 58.90; H, 6.40; N, 9.23; S, 5.24.

The following examples were prepared by the corresponding specific method outlined above using the requisite P2 fragment.

EXAMPLE B2 Isoxazole-5-carboxylic acid {(1S,2S)-1-benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

White solid: mp=82-84° C.; IR (neat, cm⁻¹) 3313, 2967, 1656, 1538, 1454, 1372, 1283, 1211, 1108, 916; ¹H NMR (DMSO-d₆) δ 8.91 (d, J=8.6, 1H), 8.67 (d, J=2.0, 1H), 8.35 (t, J=5.0, 1H), 7.31-7.08 (m, 9H), 7.03 (d, J=2.0, 1H), 5.63 (d, J=6.9, 1H), 5.02 (d, J=8.6, 1H), 4.97 (d, J=8.6, 1H), 4.60-4.30 (m, 4H), 4.14-4.00 (m, 1H), 2.90-2.75 (m, 2H), 2.23 (s, 3H), 1.49 (s, 3H), 1.28 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₂N₄O₅SNa (M+Na)⁺ 559.1986, found 559.1994; Anal. Calcd for C₂₈H₃₂N₄O₅S.0.5H₂O: C, 61.63; H, 6.10; N, 10.27. Found: C, 61.40; H, 5.91; N, 9.97.

EXAMPLE B3 Isoxazole-3-carboxylic acid {(1S,2S)-1-benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

White solid; IR (neat, cm⁻¹) 3436, 1643, 1537, 1425, 1378; ¹H NMR (DMSO-d₆) δ 9.03 (s, 1H), 8.66 (d, J=8.7, 1H), 8.32 (t, J=5.3, 1H), 7.30-7.11 (m, 9H), 6.79 (s, 1H), 5.67 (d, J=6.8, 1H), 4.97 (s, 2H), 4.47-4.32 (m, 4H), 4.09 (dd, J=15.0, 5.0, 1H), 2.84 (m, 2H), 2.24 (s, 3H), 1.49 (s, 3H), 1.34 (m, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₂N₄O₅SNa (M+Na)⁺ 559.1986, found 559.1980.

EXAMPLE B4 5-Chloro-isoxazole-3-carboxylic acid {(1S,2S)-1-benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

White solid; IR (neat, cm⁻¹) 3320, 2969, 1657, 1547, 1434, 1372, 1266; ¹H NMR (DMSO-d₆) δ 8.74 (d, J=8.2, 1H), 8.29 (t, J=5.5, 1H), 7.28-7.08 (m, 9H), 6.90 (s, 1H), 5.72 (d, J=7.1, 1H), 4.96 (s, 2H), 4.44 (m, 3H), 4.32 (dd, J=15.2, 6.0, 1H), 4.09 (dd, J=15.2, 4.6, 1H), 2.85 (m, 2H), 2.83 (s, 3H), 1.49 (s, 3H), 1.33 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₁N₄O₅SClNa (M+Na)⁺ 593.1596, found 593.1569.

EXAMPLE B5 (R)-3-{(2S,3S)-2-Hydroxy-4-phenyl-3-[(1-thiophen-2-yl-methanoyl)-amino]-butanoyl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid: mp=98-101° C.; IR (neat, cm⁻¹) 3416, 1644, 1538, 1455, 1372, 1291, 1107; ¹H NMR (DMSO-d₆) δ 8.56 (d, J=8.0, 1H), 8.38 (t, J=4.8, 1H), 7.85 (d, J=3.5, 1H), 7.69 (d, J=4.8, 1H), 7.36-7.08 (m, 10H), 5.38 (d, J=7.2, 1H), 5.10 (d, J=8.8, 1H), 4.98 (d, J=88, 1H), 4.54-4.20 (m, 5H), 2.90-2.70 (m, 2H), 2.25 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₃N₃O₄S₂Na (M+Na)⁺ 574.1805, found 574.1818; Anal. Calcd for C₂₉H₃₃N₃O₄S₂.0.75H₂O: C, 61.62; H, 6.15; N, 7.43. Found: C, 61.31; H, 5.97; N, 7.28.

EXAMPLE B6 (R)-3-{(2S,3S)-2-Hydroxy-4-phenyl-3-[(1-thiophen-3-yl-methanoyl)-amino]-butanoyl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid: mp=98-100° C.; IR (neat, cm⁻¹) 3312, 3086, 2966, 1644, 1538, 1455, 1372, 1286, 1109; ¹H NMR (DMSO-d₆) δ 8.42-8.34 (m, 2H), 8.14 (m, 1H), 7.54-7.06 (m, 1H), 5.74 (d, J=9.3, 1H), 5.35 (d, J=6.8, 1H), 4.99 (d, J=9.3, 1H), 4.53 (d, J=3.0, 1H), 4.50 (s, 1H), 4.42 (dd, J=15.0,7.0, 1H), 4.40-4.30((m, 1H), 4.15 (dd, J=15.0, 5.0, 1H), 2.90-2.70 (m, 2H), 2.26 (s, 3H), 1.50 (s, 3H), 1.35 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₃N₃O₄S₂Na (M+Na)⁺ 574.1805, found 574.1789; Anal. Calcd for C₂₉H₃₃N₃O₄S₂.1H₂O: C, 61.14; H, 6.19; N, 7.38. Found: C, 60.74; H, 5.90; N, 7.15.

EXAMPLE B7 (R)-3-{(2S,3S)-2-Hydroxy-4-phenyl-3-[((S)-1-tetrahydro-furan-2-yl-methanoyl)amino]-butanoyl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid: mp=82-84° C.; IR (neat, cm⁻¹) 3314, 2969, 1651, 1531, 1456, 1372, 1109, 1071; ¹H NMR (DMSO-d₆) δ 8.35 (t, J=6.0, 1H), 7.60 (d, J=9.2, 1H), 7.31-7.09 (m, 9H), 5.45 (d, J=6.8, 1H), 4.97 (d, J=9.5, 1H), 4.93 (d, J=9.5, 1H), 4.46 (s, 1H), 4.41-4.07 (m, 4H), 3.77-3.65 (m, 3H), 2.78-2.64 (m, 2H), 2.26 (s, 3H), 2.00-1.80 (m, 1H), 1.60 (m, 1H), 1.49 (s, 3H), 1.44-1.38 (m, 2H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₇N₃O₅SNa (M+Na)⁺ 562.2346, found 562.2345; Anal. Calcd for C₂₉H₃₇N₃O₅S.0.5H₂O: C, 63.48; H, 6.98; N, 7.66. Found: C, 63.61; H, 6.85; N, 7.58.

EXAMPLE B8 3-(2-hydroxy-3-{[1-(3-hydroxy-pyrrolidin-yl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid-2-methyl-benzylamide

¹H NMR (DMSO-d₆) δ 8.38 (t, J=5.5, 1H), 7.34-7.09 (m, 10H), 5.99 (d, J=8.2, 1H), 5.04 (d, J=9.5, 1H), 4.96 (d, J=9.5, 1H), 4.49 (s, 1H), 4.48-4.38 (m, 3H), 4.35-4.16 (m, 3H), 4.00 (m, 1H), 3.29-3.04 (m, 3H), 2.78-2.70 (m, 2H), 2.28 (s, 3H), 1.83-1.65 (m, 2H), 1.52 (s, 3H), 1.36 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₈N₄O₅SNa (M+Na)+577.2455, found 577.2473; Anal. Calcd for C₂₉H₃₉N₄O₅S.2H₂O: C, 58.96; N, 9.48. Found: C, 58.68; N, 9.11.

EXAMPLE B9 (R)-3-{(2S,3S)-2-Hydroxy-4-phenyl-3-[((R)-1-tetrahydro-furan-2-yl-methanoyl)-amino]-butanoyl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid; IR (neat, cm⁻¹) 3324, 2959, 2873, 1724, 1651, 1526, 1455, 1372, 1289, 1073; ¹H NMR (DMSO-d₆) δ 8.35 (t, J=4.9, 1H), 7.77 (d, J=8.9, 1H), 7.52-7.09 (m, 9H), 5.51 (d, J=6.6, 1H), 4.97-4.89 (m, 2H), 4.52-3.66 (m, 8H), 2.90-2.60 (m, 2H), 2.25 (s, 3H), 1.99-1.63 (m, 4H), 1.48 (s, 3H), 1.33 (s, 3H); HRMS (ESI) m/z calcd for C₂₉H₃₇N₃O₅SNa (M+Na)⁺ 562.2346, found 562.2366. Anal. Calcd for C₂₉H₃₇N₃O₅S.0.25H₂O: C, 64.01; H, 6.95; N, 7.72. Found: C, 64.20; H, 6.90; N, 7.82.

EXAMPLE B10 3,5-Dimethyl-isoxazole-4-carboxylic acid {(1S,2S)-1-benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

Isolated yield: 92%; 1H-NMR (400 MHz, dmso-d₆): δ 8.38 (t, 1H), 8.13 (d, 1H), 7.04-7.35 (m, 10H), 5.52 (d, 1H), 5.09 (d, 1H), 5.0 (d, 1H), 4.53 (m, 1H), 4.5 (s, 1H), 4.48 (m, 2H), 4.17 (dd, 1H), 2.87 (dd, 1H), 2.7 (q, 1H), 2.26 (s, 6H), 2.09 (s, 3H), 1.52 (s, 3H), 1.35 (s, 3H); IR (KBr in cm⁻¹): 3313, 1643, 1521, 743; MS (APCI, m/z): 565 (M+H), 519, 265; C30H36N4O5S1.0.69H₂O Calculated: C, 62.43; H, 6.53; N, 9.71, Observed: C, 63.81; H, 6.43; N, 9.92; HPLC: Rf (min.) 20.167; Purity: 98%.

EXAMPLE B11 2,4-Dimethyl-thiazole-5-carboxylic acid {1-benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

Isolated yield: 80%; ¹H-NMR (400 MHz, dmso d₆): δ 8.35 (t, 1H), 8.14 (d, 1H), 7.0-7.35 (m, 10H), 5.48 (d, 1H), 5.04 (d, 1H), 5.0 (d, 1H), 4.52 (m, 1H), 4.4 (s, 1H), 4.35 (m, 2H), 4.14 (dd, 1H), 2.78 (d, 2H), 2.57 (s, 3H), 2.30 (s, 3H), 2.26 (s, 3H), 1.48 (s, 3H), 1.35 (s, 3H); IR (KBr in cm⁻¹): 3310, 1641, 1534, 743; MS (APCI, m/z): 581 (M+H), 317, 265, 259; C30H36N4O4S2.0.39H₂O Calculated: C, 61.30; H, 6.31; N, 9.53, Observed: C, 62.04; H, 6.25; N, 9.65; HPLC: Rf (min.) 19.613; Purity: 98%.

EXAMPLE B12 (R)-3-{(2S,3S)-2-Hydroxy-3-[(1-methyl-1H-pyrrole-2-carbonyl)-amino]-4-phenyl-butyryl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

Isolated yield: 82%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.35 (t, 1H), 7.91 (d, 1H), 7.35-7.04 (m, 10H), 6.78 (s, 2H), 5.96 (s, 1H), 5.35 (d, 1H), 5.13 (s, 1H), 5.0 (d, 1H), 4.48 (s, 2H), 4.38 (dd, 1H), 4.30 (m, 1H), 4.13 (dd, 1H), 3.7 (s, 3H), 2.8 (m, 2H), 2.26 (s, 3H), 1.52 (s, 3H), 1.35 (s, 3H); IR (KBr in cm⁻¹): 3324, 1639, 1538, 735; MS (APCI, m/z): 549 (M+H), 503, 382, 285; C30H36N4O4S1.2.44H₂O Calculated: C, 60.80; H, 6.95; N, 9.45, Observed: C, 65.67; H, 6.61; N, 10.21; HPLC: Rf (min.) 20.745; Purity: 100%.

EXAMPLE B13 (R)-3-{((2S,3S)-3-[(1,5-Dimethyl-1H-pyrazole-4-carbonyl)-amino]-2-hydroxy-4-phenyl-butyryl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

Isolated yield: 68%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.30 (t, 1H), 7.83 (d, 1H), 7.31-7.04 (m, 10H), 6.30 (s, 1H), 5.48 (d, 1H), 4.92 (s, 2H), 4.30-4.48 (m, 4H), 4.17 (dd, 1H), 3.7 (s, 3H), 2.74 (m, 2H), 2.26 (s, 3H), 2.18 (s, 3H), 1.48 (s, 3H), 1.30 (s, 3H); IR (KBr in cm⁻¹): 3313, 1645, 1532, 744; MS (APCI, m/z): 564 (M+H), 300, 272; C30H37N5O4S1.0.5H2O Calculated: C, 62.86; H, 6.69; N, 12.22, Observed: C, 63.92; H, 6.62; N, 12.42; HPLC: Rf (min.) 19.724; Purity: 100%.

EXAMPLE B14 3-{(S)-3-[(5-Chloro-1,3-dimethyl-1H-pyrazole-4-carbonyl)-amino]-2-hydroxy-4-phenyl-butyryl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

Isolated yield: 92%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.35 (t, 1H), 7.74 (d, 1H), 7.30-7.0 (m, 10H), 5.44 (d, 1H), 4.96 (q, 2H), 4.48 (m, 1H), 4.35 (m, 2H), 4.13 (dd, 1H), 2.74 (m, 2H), 2.22 (s, 3H), 2.09 (s, 3H), 148 (s, 3H), 1.26 (s, 3H); IR (KBr in cm⁻¹): 3438, 3313, 1693, 1649, 1513, 1372, 754; MS (APCI, m/z): 598 (M+H), 334, 276, 174; C30H36N5O4S1C11.0.17H₂O Calculated: C, 59.93; H, 6.09; N, 11.65, Observed: C, 60.24; H, 6.07; N, 11.71; HPLC: Rf (min.) 19.829; Purity: 100%.

EXAMPLE B15 2-Amino-4-methyl-thiazole-5-carboxylic acid {(S)-1-benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

Isolated yield: 42%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.48 (brs, 1H), 8.35 (brs, 1H), 7.44 (d, 1H), 7.35-7.04 (m, 9H), 6.91 (s, 1H), 5.37 (d, 1H), 4.96 (q, 2H), 4.48-4.0 (m, 5H), 2,96 (m, 2H), 2.22 (2, 3H), 2.13 (s, 3H), 1.48 (s, 3H), 1.30 (s, 3H); IR (KBr in cm⁻¹): 3307, 1625, 1495; MS (APCI, m/z): 582 (M+H), 442, 318; C29H35N5O4S2Cl1 Calculated: C, 60.13; H, 6.5; N, 10.82, Observed: C, 59.87; H, 6.06; N, 12.04; HPLC: Rf (min.) 17.981; Purity: 98%.

EXAMPLE B16 3-[2-Hydroxy-3-(2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

Isolated yield: 76%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.31 (t, 1H), 8.22 (d, 1H), 7.32-7.04 (m, 13H), 5.48 (d, 1H), 5.13 (d, 1H), 5.0 (d, 1H), 4.48 (s, 2H), 4.38 (dd, 2H), 4.09 (dd, 1H), 2.83 (d, 1H), 2.70 (t, 1H), 2.26 (s, 3H), 2.01 (s, 3H), 1.48 (s, 3H), 1.33 (s, 3H); IR (KBr in cm⁻¹): 3309, 1641, 1520, 742; MS (APCI, m/z): 560 (M+H), 514, 296, 265; C32H37N3O4S1.0.64H2O Calculated: C, 67.40; H, 6.59; N, 7.37, Observed: C, 68.79; H, 6.49; N, 7.52; HPLC: Rf (min.) 21.024; Purity: 98%.

EXAMPLE B17 3-[3-(2,3-Dimethyl-benzoylamino)-2-hydroxy-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

Isolated yield: 72%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.33 (t, 1H), 8.22 (d, 1H), 7.35-6.83 (m, 12H), 5.48 (d, 1H), 5.13 (d, 1H), 5.04 (d, 1H), 4.48-4.30 (m, 4H), 4.09 (dd, 1H), 2.84 (d, 1H), 2.70 (t, 1H), 2.26 (s, 3H), 2.17 (s, 3H), 1.87 (s, 3H), 1.48 (s, 3H), 1.30 (s, 3H); IR (KBr in cm⁻¹): 3307, 1640, 1515, 743; MS (APCI, m/z): 574 (M+H), 528, 310, 265; C33H39N3O4S1.0.54H2O Calculated: C, 68.05; H, 6.76; N, 7.21, Observed: C, 69.20; H, 6.76; N, 7.34; HPLC: Rf (min.) 21.449; Purity: 99%.

EXAMPLE B18 6-Oxo-1,4,5,6-tetrahydro-pyridazine-3-carboxylic acid {1-benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl)-amide

Isolated yield: 67%; 1H-NMR (400 MHz, dmso-d₆): δ 8.35 (t, 1H), 8.09 (d, 1H), 7.30-7.0 (m, 10H), 5.6 (d, 1H), 4.91 (d, 1H), 4.83 (d, 1H), 4.44 (s, 1H), 4.30 (m, 3H), 4.17 (dd, 1H), 2.78 (d, 2H), 2.61 (t, 2H), 2.30 (t, 2H), 2.22 (s, 3H), 1.48 (s, 3H), 1.30 (s, 3H); IR (KBr in cm⁻¹): 3306, 1650, 1521, 742; MS (APCI, m/z): 566 (M+H), 520, 265; C29H35N5O5S1.0.7H2O Calculated: C, 60.23; H, 6.34; N, 12.11, Observed: C, 61.57; H, 6.24; N, 12.38; HPLC: Rf (min.) 18.455; Purity: 97%.

EXAMPLE B19 2,4-Dimethyl-5-oxo-2,5-dihydro-isoxazole-3-carboxylic acid (1-benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

Isolated yield: 73%; ¹H-NMR (400 MHz, dmso-d₆): δ 8.91 (d, 1H), 8.35 (t, 1H), 7.30-7.04 (m, 9H), 5.70 (d, 1H), 5.0 (d, 2H), 4.44 (s+m, 3H), 4.31 (dd, 1H), 4.13 (dd, 1H), 2.91 (s+m, 4H), 2.65 (t, 1H), 2.22 (s, 3H), 1.52 (s, 3H), 1.48 (s, 3H), 1.30 (s, 3H); IR (KBr in cm⁻¹): 3325, 2932, 1729, 1649, 1527, 742; MS (APCI, m/z): 581 (M+H), 539, 493, 225; C30H36N4O6S1 Calculated: C, 62.29; H, 5.61; N, 9.19, Observed: C, 62.05; H, 6.25; N, 9.65; HPLC: Rf (min.) 19.638; Purity: 100%.

EXAMPLE B20 (R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2,4-dimethyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid allylamide

¹H NMR (DMSO-d₆) δ 8.23 (s, 1H), 8.10-8.03 (m, 2H), 7.33-7.12 (m, 5H), 6.85 (d, J=7.7, 1H), 6.51 (d, J=7.7, 1H), 5.82-5.70 (m, 1H), 5.44 (d, J=6.8, 1H), 5.22-4.97 (m, 4H), 4.50-4.30 (m, 3H), 3.84-3.60 (m, 2H), 2.84-2.66 (m, 2H), 2.13 (s, 3H), 1.85 (s, 3H), 1.49 (s, 3H), 1.35 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₆N₃O₅S (M+H)⁺ 526.2376, found 526.2380; Anal. Calcd for C₂₈H₃₅N₃O₅S.0.2TFA: C, 62.19; H, 6.47; N, 7.66. Found: C, 62.27; H, 6.78; N, 7.26.

EXAMPLE B21 3-(2-Hydroxy-3-{[1-(3-hydroxy-2,4-dimethyl-phenyl)-methyanoyl]-amino}-4-phenyl-butznoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid prop-2-ynylamide

¹H NMR (DMSO-d₆) δ 8.40 (t, J=5.4, 1H), 8.22 (s, 1H), 8.02 (d, J=8.2, 1H), 7.35-6.52 (m, 7H), 5.44 (d, J=6.8, 1H), 5.10 (d, J=9.1, 1H), 5.02 (d, J=9.1, 1H), 4.46-4.40 (m, 2H), 4.40 (s, 1H), 3.86 (s br, 2H), 3.08 (t, J=1.8, 1H), 2.82-2.72 (m, 2H), 2.15 (s, 3H), 1.88 (s, 3H), 1.51 (s, 3H), 1.37 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₄N₃O₅S (M+H)⁺ 524.2219, found 524.2219; Anal. Calcd for C₂₈H₃₃N₃O₅S.0.5H2O: C, 63.13; H, 6.43; N, 7.89; S, 6.02. Found: C, 62.80; H, 6.64; N, 7.71; S, 5.69.

EXAMPLE B22 3-{2-Hydroxy-3-[(1-methyl-1H-pyrrole-2-carbonyl)-amino]-4-phenyl-butyryl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-chloro-benzylamide Chiral

Isolated yield: 50%; ¹H-NMR (400 MHz, dmso-d⁶): 6.40-7.40 (m, 1H), 6.00 (m, 1H), 4.20-5.20 (m, 7H), 3.71, 3.54 (s 3H), 2.70-2.90 (m, 2H), 1.52 (d, J=2.0 Hz, 3H), 1.32 (d, J=2.1 Hz, 3H); MS (APCI, m/z): 570 (M+H).

EXAMPLE B23 3,5-Dimethyl-isoxazole-4-carboxylic acid {1-benzyl-3-[4-(2-chloro-benzylcarbamoyl)-5,5-dimethyl-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl]-amide

Isolated yield: 55%; ¹H-NMR (400 MHz, dmso-d⁶): 7.00-7.40 (m, 9H), 4.36-5.08 (m, 7H), 2.70-2.90 (m, 2H), 2.34,2.25 (s, 3H), 2.18,2.12 (s, 3H), 1.56 (d, J=8.5 Hz, 3H), 1.35 (d, J=6.2 Hz, 3H); MS (APCI, m/z): 586 (M+H); C₂₉H₃₃ClN₄O₅S.0.42H₂O Calculated: C, 58.77; H, 5.75; N, 9.45, Observed: C, 58.37; H, 5.73; N, 9.19.

EXAMPLE B24 3-{2-Hydroxy-3-[(1-methyl-1H-pyrrole-2-carbonyl)-amino]4-phenyl-butyryl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2,6-difluoro-benzylamide

Isolated yield: 75%; 1H-NMR (400 MHz, dmso-d⁶): 6.40-7.40 (m, 10H), 6.00 (m, 1H), 4.20-5.20 (m, 7H), 3.64, 3.61 (s 3H), 2.70-2.90 (m, 2H), 1.52, 1.49 (s, 3H), 1.33, 1.29 (s, 3H); MS (APCI, m/z): 571 (M+H); C₂₉H₃₂F₂N₄O₄S Calculated: C, 61.04; H, 5.65; N, 9.82, Observed: C, 60.86; H, 5.94; N, 9.71.

EXAMPLE B25 3,5-Dimethyl-isoxazole-4-carboxylic acid {1-benzyl-3-[4-(2,6-difluoro-benzylcarbamoyl)-5,5-dimethyl-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

Isolated yield: 75%; ¹H-NMR (400 MHz, dmso-d⁶): 6.60-7.40 (m, 8H), 4.26-5.08 (m, 7H), 2.70-2.90 (m, 2H), 2.32, 2.28 (s, 3H), 2.16,2.13 (s, 3H), 1.56,1.53 (s, 3H), 1.37, 1.34 (s, 3H); MS (APCI, m/z): 587 (M+H); C₂₉H₃₂F₂N₄O₅S Calculated: C, 59.37; H, 5.50; N, 9.55, Observed: C, 59.12; H, 5.88; N, 9:50.

EXAMPLE B26 3-{2-Hydroxy-3-[(1-methyl-1H-pyrrole-2-carbonyl)-amino]-4-phenyl-butyryl}-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-trifluoromethyl-benzylamide

Isolated yield: 83%; ¹H-NMR (400 MHz, dmso-d⁶): 6.40-7.60 (m, 1H), 6.00 (m, 1H), 4.20-5.20 (m, 7H), 3.70, 3.54 (s 3H), 2.70-2.90 (m, 2H), 1.52 (s, 3H), 1.36, 1.29 (s, 3H); MS (APCI, m/z): 619 (M+H); C₃₀H₃₃F₃N₄O₄S Calculated: C, 59.79; H, 5.52; N, 9.30, Observed: C, 59.42; H, 5.55; N, 9.06.

EXAMPLE B27 3,5-Dimethyl-isoxazole-4-carboxylic acid {1-benzyl-3-[5,5-dimethyl-4-(2-trifuoromethyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

Isolated yield: 93%; ¹H-NMR (400 MHz, dmso-d⁶): 7.05-7.60 (m, 9H), 4.36-5.08 (m, 7H), 2.70-2.90 (m, 2H), 2.30, 2.21 (s, 3H), 2.15, 2.05 (s, 3H), 1.54, 1.52 (s, 3H), 1.39, 1.32 (s, 3H); MS (APCI, m/z): 619 (M+H); C₃₀H₃₃F₃N₄O₅S Calculated: C, 58.24; H, 5.38; N, 9.06, Observed: C, 57.87; H, 5.68; N, 9.02.

EXAMPLE B28 N-[(1S,2S)-3-(4-Allylcarbamoyl-5,5-dimethyl-thiazolidin-3-yl)-1-benzyl-2-hydroxy-3-oxo-propyl]-nicotinamide

White solid: ¹H NMR (DMSO-d₆) δ 8.81 (d, J=8.6, 1), 8.77 (d, J=6.2, 1H), 8.12 (m, 1H), 7.99 (m, 1H), 7.63 (m, 1H), 7.32-7.12 (m, 7H), 5.78 (m, 1H), 5.18 (m, 2H), 4.56 (m, 3H), 4.40 (m, 4H), 2.87-2.67 (m, 2H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₂₆H₃₂N₄O₄S.0.5H₂O.0.5 TFA) calculated C (57.65), H (6.36), N (10.19), found C (57.73), H (5.91), N (10.15). HRMS (ESI) m/z calcd for 483.2075, found 497.2066.

EXAMPLE B29 3-[2-Hydroxy-3-(4-methoxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

Isolated yield: 5.6%. ¹H NMR (400 MHz, DMSO-d₆): δ 8.32 (t, 1H), 8.09 (d, 1H), 7.33-7.27 (m, 3H), 7.23-7.19 (m, 2H), 7.15-7.08 (m, 5H), 6.69 (d, 2H), 5.46 (d, 1H), 5.13 (d, 1H), 4.99 (d, 1H), 4.49 (s, 2H), 4.41-4.36 (m, 2H), 4.10 (dd, 1H), 3.71 (s, 3H), 2.84-2.81 (m, 1H), 2.72 (t, 1H), 2.24 (s, 3H), 2.07 (s, 3H), 1.48 (s, 3H), 1.33 (s, 3H); MS-APCI (m/z+): 326, 590 (M+H). HPLC: Rf (min.) 21.26; Purity: 100%; C₃₃H₃₉N₃O₅S1.0.4H₂O: calcd: C, 66.40; H, 6.72; N, 7.04, found: C, 66.38; H, 6.71; N, 6.94.

EXAMPLE B30 (R)-3-((2S,3S)-2-Hydroxy-4-phenyl-3-[(1-o-tolyl-methanoyl)-amino]-butanoyl}-5,5-dimethyl-thiazolidine-4-carboxylic acid propylamide

IR (neat, cm⁻¹) 3318, 2964, 1642, 1530, 1445, 1372, ¹H NMR (DMSO) 88.21 (d, J=8.4, 1H), 7.90 (t, J=5.6, 1H), 7.35-7.07 (m, 9H), 5.45 (d, J=6.8, 1H), 5.09 (d, J=9.2, 1H), 5.00 (d, J=9.2, 1H), 4.50-4.38 (m, 2H), 4.37 (s, 1H), 3.01 (q, J=6.9, 2H), 2.90-2.60 (m, 2H), 2.02 (s, 3H), 1.49 (s, 3H), 1.44-1.35 (m, 2H), 1.34 (s, 3H), 0.82 (t, J=7.5, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₆N₃O₄S (M+H)⁺ 498.2424, found 498.2427.

EXAMPLE B31 (R)-3-((2S,3S)-3-{[1-(3-Fluoro-2-methyl-phenyl)-methanoyl]-amino}-2-hydroxy-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid propylamide

White solid: ¹H NMR (DMSO) δ 8.34 (d, J=8.1, 1H), 7.91 (t, J=5.9, 1H), 7.40-7.10 (m, 7H), 6.93 (d, J=6.9, 1H), 5.51 (d, J=6.2, 1H), 5.08 (d, J=8.8, 1H), 5.00 (d, J=8.8, 1H), 4.50-4.39 (m, 2H), 4.38 (s, 1H), 3.00 (dd, J=12.3, 5.9, 2H), 2.90-2.60 (m, 2H), 1.89 (s, 3H), 1.49 (s, 3H), 1.40-1.34 (m, 2H), 1.34 (s, 3H), 0.82 (t, J=7.7, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₅N₃O₄FS (M+H)⁺ 516.2332, found 516.2339.

EXAMPLE B32 (R)-3-((2S,3S)-3-{[1-(3-Fluoro-2-methyl-phenyl)-methanoyl]-amino}-2-hydroxy-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 3-methoxy-benzylamide

White solid: ¹HNMR (DMSO) δ8.43 (t, J=5.9, 1H), 8.34 (d, J=8.1, 1H), 7.31-6.72 (m, 12H), 5.57 (d, J=6.8, 1H), 5.12 (d, J=9.3, 1H), 5.01 (d, J=9.3, 1H), 4.50-4.30 (m, 4H), 4.12 (dd, J=15.7,5.9, 1H), 3.69 (s, 3H), 2.95-2.62 (m, 2H), 1.90 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₇N₃O₅SF (M+H)⁺ 594.2434, found 594.2438.

EXAMPLE B33 (R)-3-((2S,3S)-3-{[1-(3-Fluoro-2-methyl-phenyl)-methanoyl]-amino}-2-hydroxy-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid allylamide

White solid: ¹H NMR (DMSO) δ 8.34 (d, J=8.3, 1H), 8.10 (t, J=5.7, 1H), 7.40-6.90 (m, 8H), 5.81-5.69 (m, 1H), 5.54 (d, J=6.6, 1H), 5.30-4.90 (m, 4H), 4.50-4.35 (m, 3H), 3.80-3.65 (m, 2H), 2.90-2.60 (m, 2H), 1.89 (s, 3H), 1.49 (s, 3H), 1.35 (s, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₃N₃O₄SF (M+H)⁺ 514.2182, found 514.2176.

EXAMPLE B34 3-[(2S,3S)-2-Hydroxy-3-(3-hydroxy-2,5-dimethyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid allylamide

¹H NMR (DMSO-d₆) δ 9.23 (s, 1H), 8.09 (m, 2H), 7.35-7.17 (m, 5H), 6.60 (s, 1H), 6.37 (s, 1H), 5.74 (m, 1H), 5.41 (brs, 1H), 5.20 (dd, J=17.2, 1.6, 1H), 5.11 (d, J=9.2, 1H), 5.02 (dd, J=10.2, 1.5, 1H), 5.00 (d, J=9.1, 1H), 4.46-4.37 (m, 3H), 3.79 (ddd, J=15.9, 5.5, 5.3, 1H), 3.63 (ddd, J=15.9, 5.4, 5.3, 1H), 2.82 (dd, J=13.9, 0.3, 1H), 2.71 (dd, J=13.6, 10.7, 1H), 2.16 (s, 3H), 1.76 (s, 3H), 1.51 (s, 3H), 1.36 (s, 3H); Anal. Calcd for C₂₈H₃₅N₄O₅S.0.3H₂O: C, 63.32; H, 6.76; N, 7.91, Found: C, 63.35; H, 6.70; N, 7.71.

EXAMPLE B35 3-[(2S,3S)-3-(5-Fluoro-3-hydroxy-2-methyl-benzoylamino)-2-hydroxy-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid allylamide

¹H NMR (DMSO-d₆) δ 9.94 (s, 1H), 8.23 (d, J=8.2, 1H), 8.10 (t, J=5.6, 1H), 7.33-7.17 (m, 5H), 6.58 (dd, J=10.6, 2.5, 1H), 6.32 (dd, J=8.8, 2.5, 1H), 5.78 (m, 1H), 5.54 (brs, 1H), 5.21 (dd, J=17.2, 1.7, 1H), 5.10 (d, J=9.1, 1H), 5.03 (dd, J=10.2, 1.5, 1H), 5.01 (d, J=9.1, 1H), 4.50-4.42 (m, 3H), 3.78 (ddd, J=15.9, 5.4, 5.4, 1H), 3.63 (ddd, J=15.9, 5.4, 5.3, 1H), 2.84 (dd, J=14.5,3.3, 1H), 2.70 (dd, J=13.5, 10.3, 1H), 1.75 (s, 3H), 1.50 (s, 3H), 1.36 (s, 3H); Anal. Calcd for C₂₇H₃₂FN₃O₅S.0.3H₂O: C, 60.61; H, 6.14; N, 7.85, Found: C, 60.63; H, 6.08; N, 8.07.

EXAMPLE B36 (R)-3-((2S,3S)-3-{[1-(3-Fluoro-2-methyl-phenyl)-methanoyl]-amino}-2-hydroxy-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

¹H NMR (DMSO) δ 8.85-8.35 (m, 2H), 7.38-6.90 (m, 12H), 5.55 (d, J=5.9, 1H), 5.12 (d, J=9.2, 1H), 5.01 (d, J=9.2, 1H), 4.58-4.32 (m, 4H), 4.10 (dd, J=15.0,4.6, 1H), 2.92-2.62 (m, 2H), 2.24 (s, 3H), 1.90 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₇N₃O₄FS (M+H)⁺ 578.2489, found 578.2486; Anal. Calcd for C₃₂H₃₆N₃O₄FS.0.2 EtOAc: C, 66.17; H, 6.37; N, 7.06. Found: C, 66.30; H, 6.54; N, 6.74.

EXAMPLE B37 (R)-3-((2S,3S)-3-{[1-(4-Fluoro-2-methyl-phenyl)-methanoyl]-amino}-2-hydroxy-4-phenyl-butanoyl)-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid: ¹H NMR (DMSO) δ 8.40-8.30 (m, 2H), 7.35-6.90 (m, 12H), 5.53 (d, J 6.8, 1H), 5.13 (d, J=9.0, 1H), 5.00 (d, J=9.0, 1H), 4.48 (s, 1H), 4.47-4.45 (m, 2H), 4.38 (dd, J=15.0, 5.9, 1H), 4.10 (dd, J=15.0, 4.8, 1H), 2.90-2.62 (m, 2H), 2.24 (s, 3H), 2.04 (s, 3H), 1.48 (s, 3H), 1.33 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₇N₃O₄SF (M+H)⁺ 578.2463, found 578.2489.

EXAMPLE B38 Nicotinic acid 3-[(1S,2S)-3-((R)-4-allylcarbamoyl-5,5-dimethyl-thiazolidin-3-yl)-1-benzyl-2-hydroxy-3-oxo-propylcarbamoyl]-2-methyl-phenyl ester

White solid: ¹H NMR (DMSO) δ 9.26 (dd, J=2.0, 0.9, 1H), 8.90 (dd, J=5.6, 2.0, 1H), 8.47 (dt, J=7.9,2.0, 1H), 8.40 (d, J=8.2, 1H), 8.1 (t, J=5.7, 1H), 7.65 (ddd, J=7.9, 5.6, 0.9, 1H), 7.40-7.10 (m, 8H), 5.82-5.68 (m, 1H), 5.6 (d, J=6.2, 1H), 5.30-4.90 (m, 4H), 4.50-4.40 (m, 2H), 4.40 (s, 1H), 3.80-3.70 (m, 2H), 3.00-2.60 (m, 2H), 1.85 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H).

EXAMPLE B39 (R)-3-[(2S,3S)-2-Hydroxy-3-(4-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid: ¹H NMR (DMSO) δ 9.55 (s, 1H), 8.32 (t, J=4.9, 1H), 8.00 (d, J=8.4, 1H), 7.36-7.00 (m, 10H), 6.54-6.48 (m, 2H), 5.44 (d, J=6.6, 1H), 5.13 (d, J=9.2, 1H), 4.99 (d, J=9.2, 1H), 4.50-4.32 (m, 4H), 4.11 (dd, J=15.0, 4.8, 1H), 3.50-2.80 (m, 2H), 2.25 (s, 3H), 2.04 (s, 3H), 1.49 (s, 3H), 1.33 (s, 3H); Anal. Calcd for C₃₂H₃₇N₃O₅S.0.25H₂O: C, 66.24; H, 6.51; N, 7.24. Found: C, 66.25; H, 6.55; N, 7.35.

EXAMPLE B40 6-Amino-pyridine-2-carboxylic acid {(1S,2S)-1-benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl)-amide

¹H NMR (DMSO-d₆) δ 8.44 (d, 1H, J=5.6), 8.36 (d, 1H, J=9.3), 7.69-7.49 (t, 1H, J 0.7), 7.34-7.06 (m, 10H), 6.61 (d, 1H, J=8.4), 6.27 (br s, 2H) 5.47 (d, 1H, J=7.1), 0.00 (m, 2H), 4.54-4.43 (m, 2H), 4.50 (s, 1H), 4.38 (dd, 1H, J=6.4, 15.2), 4.19 (dd, 1H, J=4.6, 14.7), 2.87-2.65 (m, 2H), 2.28 (s, 3H), 1.53 (s, 3H), 1.38 (s, 3H). Exact mass calculated for C₃₀H₃₆N₅O₄S (M+H)⁺ 562.2488, found 562.2493.

EXAMPLE B41 ((1S,2S)-1-Benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-2,3-dichloro-isonicotinamide

¹H NMR (DMSO-d₆) δ 8.89 (d, 1H, J=8.42), 8.40 (t, 1H, J=5.5), 8.38 (d, 1H, J=4.8), 7.30-7.08 (m, 10H), 5.58 (d, 1H, J=7.3), 5.07 (d, 1H, J=8.8), 5.00 (d, 1H, J=8.8), 4.54-4.50 (m, 1H), 4.51 (s, 1H), 4.43-4.36 (m, 2H), 4.16 (dd, 1H, J=5.1, 15.0), 2.89-2.85 (m, 1H), 2.71-2.63 (m, 1H), 2.26 (s, 3H), 1.50 (s, 3H), 1.35s (s, 3H). Exact mass calculated for C₃₀H₃₃N₄O₄SCl₂ (M+H)⁺ 615.1600, found 615.1581. Anal. Calcd for C₃₀H₃₂N₄O₄SCl₂: C, 58.54; H, 5.24; N, 9.10. Found: C, 58.48; H, 5.10; N, 8.80.

EXAMPLE B42 {(1S,2S)-Benzyl-3-[(R)-5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-3-chloro-isonicotinamide

¹H NMR (DMSO-d₆) δ 8.82 (d, 1H, J=8.6), 8.62 (s, 1H), 8.52 (d, 1H, J=4.9), 8.39 (d, 1H, J=5.1), 7.29-7.09 (m, 10H), 5.54 (d, 1H, J=7.1), 5.09 (d, 1H, J=9.0), 4.99 (d, 1H, J=9.0), 4.56-4.49 (m, 1H), 4.51 (s, 1H), 4.44-4.37 (m, 2H), 4.15 (dd, 1H, J=5.1, 15.0), 2.88-2.83 (m, 1H), 2.74-2.65 (m, 1H), 2.26 (s, 3H), 1.50 (s, 3H), 1.35s (s, 3H). Exact mass calculated for C₃₀H₃₃N₄O₄SCl (M)⁺ 581.1989, found 581.1983.

EXAMPLE B43 (R)-3-[(2S,3S)-2-Hydroxy-3-(3-hydroxy-2,5-dimethyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid 2-methyl-benzylamide

¹H NMR (DMSO-d₆) δ 9.24 (s, 1H), 8.31 (t, J=5.6, 1H), 8.10 (d, J=8.2, 1H), 7.34-7.09 (m, 9H), 6.60 (s, 1H), 6.38 (s, 1H), 5.42 (br s, 1H), 5.14 (d, J=9.1, 1H), 5.01 (d, J=9.1, 1H), 4.50 (s, 1H), 4.50-4.37 (m, 3H), 4.11 (dd, J=15.1, 4.7, 1H), 2.76 (m, 2H), 2.26 (s, 3H), 2.16 (s, 3H), 1.77 (s, 3H), 1.50 (s, 3H), 10.35 (s, 3H); HRMS (ESI) m/z calcd for C₃₃H₄₀N₃O₅S (M+H)⁺ 590.2689, found 590.2676; Anal. Calcd for C₃₃H₃₉N₃O₅S.0.3H₂O: C, 66.60; H, 6.71; N, 7.06. Found: C, 66.65; H, 6.69; N, 7.05.

EXAMPLE B44 N-{(1S,2S)-1-Benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-2-methyl-nicotinamide

White solid: ¹H NMR (DMSO-d₆) δ 8.53-8.33 (m, 2H), 7.47 (d, J=7.82, 1H), 7.38-7.10 (m, 12H), 5.62 (d, J=7.94, 1H), 5.18 (dd, J=9.6, 7.6, 2H), 4.43-4.37 (m, 3H), 4.17 (dd, J=7.81, 6.99, 1H), 2.87-2.67 (m, 2H), 2.28 (s, 3H), 2.21 (s, 3H), 1.49 (s 3H), 1.34 (s, 3H); Anal. (C₃₁H₃₆N₄O₄S.1.0H₂O.1.0MeCN) calculated C (63.95), H (6.67), N (11.30), found C (63.94), H (6.75), N (11.26). HRMS (ESI) m/z calcd for 561.2544, found 561.2556.

EXAMPLE B45 Pyridine-2-carboxylic acid {(1S,2S)-1-benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-amide

White solid: ¹H NMR (DMSO-d₆) δ 8.89 (d, J=7.86,), 8.66 (d, J=4.2, 1H), 8.39 (t, J=6.54, 1H), 7.89 (m 2H), 7.32-7.12 (m, 9H), 5.68 (d, J=7.28, 1H), 5.03 (dd J=9.7, 8.3, 2H), 4.56(m 3H), 4.40 (d, J=7.5, 1H), 4.35 (d, J=7.5, 1H), 4.21 (d, J=6.7, 1H), 2.87-2.67 (m, 2H), 2.25 (s 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₃₀H₃₄N₄O₄S.0.1H₂O.0.1 EtOAc) calculated C (65.52), H (6.33), N (10.05), found C (65.78), H (6.69), N (9.66). HRMS (ESI) m/z calcd for 547.2380, found 547.2373.

EXAMPLE B46 Pyridine-2-5-hydroxy-carboxylic acid {(1S,2S)-1-benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}--amide

White solid: ¹H NMR (DMSO-d₆) δ 8.89 (d, J=7.9, 1), 8.66 (d, J=4.2, 1H), 8.39 (t, J=6.54, 1H), 7.89 (m 2H), 7.32-7.12 (m, 9H), 5.68 (d, J=7.2, 1H), 5.03 (dd J=9.7, 8.3, 2H), 4.56 (m 3H), 4.40 (d, J=7.5, 1H), 4.35 (d, J=7.5, 1H), 4.21 (d, J=6.7, 1H), 2.87-2.67 (m, 2H), 2.25 (s 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₃₀H₃₄N₄O₅S.0.5H₂O.0.5 EtOAc) calculated C (62.29), H (6.42), N (9.91), found C (62.53), H (6.84), N (10.10). HRMS (ESI) m/z calcd for 563.2325, found 563.2328.

EXAMPLE B47 N-{(1S,2S)-1-Benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-nicotinamide

White solid ¹H NMR (DMSO-d₆) δ 8.89 (d, J=7.9, 1H), 8.66 (d, J=4.2, 1H), 8.39 (t, J=6.54, 1H), 7.89 (m 2H), 7.32-7.12 (m, 9H), 5.68 (d, J=7.3, 1H), 5.03 (dd J=9.7, 8.3, 2H), 4.56(m 3H), 4.40 (d, J=7.5, 1H), 4.35 (d, J=7.5, 1H), 4.21 (d, J=6.7, 1H), 2.87-2.67 (m, 2H), 2.25 (s 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₃₀H₃₄N₄O₄S.0.5H₂O.0.5 MeCN) calculated C (64.61), H (6.39), N (10.94), found C (65.02), H (6.58), N (10.90). HRMS (ESI) m/z calcd for 547.2372, found 547.2379.

EXAMPLE B48 N-{(1S,2S)-1-Benzyl-3-[5,5-dimethyl-4-(2-methyl-benzylcarbamoyl)-thiazolidin-3-yl-2-hydroxy-3-oxo-propyl}-nicotinamide

White solid: ¹H NMR (DMSO-d₆) δ 8.89 (d, J=7.9, 1H), 8.66 (d, J=4.2, 1H), 8.39 (t, J=6.54, 1H), 7.89 (m 2H), 7.32-7.12 (m, 9H), 5.68 (d, J=7.28, 1H), 5.03 (dd J=9.7, 8.3, 2H), 4.56 (m, 3H), 4.40 (d, J=7.5, 1H), 4.35 (d, J=7.5, 1H), 4.21 (d, J=6.7, 1H), 2.87-2.67 (m, 2H), 2.25 (s 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₃₀H₃₄N₄O₅S.1.3H₂O) calculated C (61.42), H (6.32), N (9.49), found C (61.64), H (6.17), N (9.12). HRMS (ESI) m/z calcd for 563.2326, found 563.2328.

EXAMPLE B49 N-[(1S,2S)-3-(4-Allylcarbamoyl-5,5-dimethyl-thiazolidin-3-yl)-1-benzyl-2-hydroxy-3-oxo-propyl]-2-methyl-nicotinamide

White solid: ¹H NMR (DMSO-d₆) δ 8.58 (m, 1H), 8.29 (d, J=7.54, 1H), 7.78 (d, J=7.88, 2H), 7.32-7.12 (m, 7H), 5.78 (m, 1H), 5.18 (dd J=9.7,8.3, 2H), 4.56 (m, 3H), 4.40 (m, 4H), 2.87-2.67 (m, 2H), 2.25 (s 3H), 1.49 (s, 3H), 1.34 (s, 3H); Anal. (C₂₆H₃₂N₄O₄S.0.5H₂O.0.5 TFA) calculated C (57.68), H (6.66), N (8.31), found C (57.66), H (6.18), N (8.77). HRMS (ESI) m/z calcd for 497.2232, found 497.2223.

The synthesis of compounds with the general structure 24 is as follows. The boc-protected carboxylic acids 20a-f are coupled to the requisite amines 2 to yield amino amides 23 using a two step process. The process includes treatment of 20 with 2 in the presence of either diphenyl chlorophosphate or EDCI, followed by exposure to HCl or methane sulfonic acid. Final compounds 24 are obtained by a DCC-mediated coupling of 23 and 4 followed by deprotection of the P2 phenol. Final compounds were purified either by flash chromatography or preparative HPLC.

The synthesis of compounds of the general structure 31 (where P2 is not 2-methyl-3-hydroxy benzamide) is as follows. Amino amides of the general structure 23 were coupled to the Boc-acid intermediate 15 using DCC coupling conditions. The resulting intermediate 29 was deprotected under acidic conditions to yield amine of the general structure 30. Final compounds were obtained by modification of amine 30 by methods described in General Methods B section to give P2 amides and ureas.

Methods Used for Synthesis of Compounds with P1 Variations.

EDCI coupling—To a solution of acid, amine and HOBT in CH₂Cl₂ was added EDCI and the solution stirred overnight at room temperature. The solution was concentrated in vacuo and the residue dissolved in ethyl acetate and a small portion of water. The solution was washed with saturated NH₄Cl (2×), saturated NaHCO₃ (2×), brine (1×), dried with MgSO₄ and concentrated in vacuo. The crude used without further purification unless otherwise noted.

DCC coupling—A solution of acid, amine and HOBT was prepared in ethyl acetate. To the solution was then added DCC in an EtOAc solution at 0° C. and the mixture was stirred overnight at room temperature. The mixture was filtered and the filtrate was concentrated in vacuo. The residue dissolved in ethyl acetate washed with saturated NH₄Cl (1×), saturated NaHCO₃ (1×), brine (1×), dried over Na₂SO₄ and concentrated in vacuo. The crude was used without further purification unless otherwise noted.

4N HCl Boc deprotection—To a solution of Boc-amine in dioxane was added 4N HCl solution in dioxane and the solution stirred overnight at room temperature. The solution was poured into saturated NaHCO₃ and the product was extracted into ethyl acetate. The organic solution was washed with brine, dried over Na₂SO₄ and concentrated in vacuo. The crude was used without further purification unless otherwise noted.

MeSO₃H Boc deprotection—To a solution of Boc-amine in ethyl acetate at 0° C. was added methane sulfonic acid and the solution stirred 3-6 h at room temperature. The solution was cooled to 0° C. and sufficient saturated NaHCO₃ was added to quench the acid. The solution was diluted with ethyl acetate, washed with saturated NaHCO₃ and brine, dried over Na₂SO₄ and concentrated in vacuo. The crude used without further purification unless otherwise noted.

KCN Phenolic acetate deprotection—A solution of phenolic acetate and KCN in ethanol was heated at 50° C. overnight. The solution was concentrated in vacuo. The residue was purified by flash chromatography eluted with 0 to 5% methanol in CH₂Cl₂ unless otherwise noted.

NaOMe/MeOH Phenolic acetate deprotection—0.5 N NaOCH₃/MeOH Phenolic acetate deprotection—A solution of phenolic acetate in EtOAc and methanol was cooled to 0° C. in an ice bath. 0.5 N NaOCH₃/MeOH was then added dropwise and then stirred at 0° C. for 1.5-2 hrs following addition. Additional EtOAc was then added, the 0.15 N HCl (4.5 eq.) added dropwise. The phases were separated and organic phase washed with 2.5% Na₂CO₃ aqueous solution, then with 0.1 N HCl/brine (2:1), followed with brine, dried with MgSO₄ and concentrated in vacuo. The resulting residue subjected to flash silica gel chromatography to afford the desired product unless otherwise noted.

HCl/MeOH Phenolic acetate deprotection—To a solution of phenolic acetate in methanol was added 4N HCl in dioxane and the solution stirred at room temperature ca. 4 h. The solution was concentrated in vacuo. The residue was purified by flash chromatography eluted with 0 to 5% methanol in CH₂Cl₂ unless otherwise noted. Fragments of the General Structure 20.

Source of Boc-carboxylic Acids 20a-f

Boc-acids 20a and 20b were prepared following the procedure of Demange, L.; Menez, A.; Dugave, C. Tet. Lett. 1998, 39, 1169.

Boc-acids 20c, 20d, 20e and 20f were prepared following the procedure of Karanewsky, D.; et al. J. Med. Chem. 1990, 33, 1459.

Specific Method C

EXAMPLE C1 (S)-4,4-Difluoro-1-[(2S,3S)-2-hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-pyrrolidine-2-carboxylic acid 2-methyl-benzylamide.

The title compound was prepared according to general methods using the corresponding Boc-protected pyrrolidinic acid (0.96 g, 3.8 mmol), o-methylbenzyl amine (0.57 mL, 4.6 mmol), HOBT (0.62 g, 4.6 mmol), EDCI (0.88 g, 4.6 mmol), CH₂Cl₂ (50 mL). To give the crude Boc-amide (MS-APCI (m/z+): 355, 255) (1.35 g, 3.8 mmol). The Boc was removed using the general 4N HCl Boc deprotection. 4N HCl in 1,4-dioxane (5 mL), 1,4-dioxane (5 mL). The result was amino amide of general structure 23. Isolated yield: 0.79 g (71%, 2 steps). ¹H NMR (400 MHz, DMSO-d₆): δ 9.02 (t, 1H), 7.24-7.14 (m, 4H), 4.55 (t, 1H), 4.35 (dd, 1H), 4.30 (dd, 1H), 3.73 (m, 2H), 2.94 (m, 2H), 2.52 (m, 1H), 2.27 (s, 3H); ¹⁹F NMR (376 MHz, DMSO-d₆): 6-95.3 (dq, J=235, 15 Hz, 1F), 96.5 (dq, J=235, 12 Hz, 1F); MS-APCI (m/z+): 255.

Amino amide 23 (100 mg, 0.34 mmol) was coupled to carboxylic acid 4 (140 mg, 0.38 mmol) using the general DCC coupling method outlined above. HOBT (51 mg, 0.38 mmol), DCC (78 mg, 0.38 mmol), TEA (50 μL, 0.36 mmol), CH₂Cl₂ (10 mL). The crude was purified by chromatography eluted with 10% acetone in CH₂Cl₂. Isolated yield: 0.13 g (63%). MS-APCI (m/z+): 608. This material was subjected to the general KCN phenolic acetate deprotection conditions (130 mg, 0.21 mmol), KCN (1 mg, 15 μmol), ethanol (10 mL). The crude was precipitated from diethyl ether and ethyl acetate with hexanes at −78° C. Isolated yield: 0.110 g (84%). ¹H NMR (400 MHz, DMSO-d₆): δ 9.37 (s, 1H), 8.36 (t, 1H), 8.16 (d, 1H), 7.32-7.09 (m, 9H), 6.93 (t, 1H), 6.76 (d, 1H), 6.54 (d, 1H), 5.49 (d, 1H), 4.66 (dd, 1H), 4.34-4.15 (m, 6H), 2.85-2.67 (m, 3H), 2.40 (m, 1H), 2.22 (s, 3H), 1.79 (s, 3H); ¹⁹F NMR (376 MHz, DMSO-d₆): δ −98.7 (m, 2F); MS-APCI (m/z+): 566; HPLC Purity: 100%; Rf (min.) 19.01; Anal. C₃₁H₃₃N₃O₅F₂.0.3H₂° C., H, N calcd: C, 65.21; H, 5.93; N, 7.36; found: C, 65.11; H, 5.90; N, 7.17.

EXAMPLE C2 (2S,4R)-4-Fluoro-1-[(2S,3S)-2-hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-pyrrolidine-2-carboxylic acid 2-methyl-benzylamide

Isolated material was subjected to flash silica gel chromatography, eluting with EtOAc/hexanes (50/50) then with EtOAc EtOAc/hexanes (4:1) to afford the title compound. ¹H NMR (400 MHz, DMSO-d₆): δ 9.37 (s, 1H), 8.46 (t, 1H), 8.21 (d, 1H), 7.34 (d, 2H), 7.26 (d, 2H), 7.21 (t, 2H), 7.15-7.07 (m, 3H), 6.94 (t, 1H), 6.76 (d, 1H), 6.56 (d, 1H), 5.51+5.38 (bs+bs, 1H), 5.06 (d, 1H), 4.58 (t, 1H), 4.45 (dd, 1H), 4.35-4.27 (m, 2H), 4.21-4.09 (m, 3H), 3.94-3.91+3.84-3.81 (m+m, 1H), 2.69 (d, 2H), 2.23 (s, 3H), 2.19-2.01 (m, 1N), 1.83 (s, 3H); MS-APCI (m/z+): 548; HPLC: Rf (min.) 18.72; Purity: 96%. Anal. C₃₁H₃₄N₃O₅F.0.3H₂O calcd: 67.33, 6.31, 7.60, found: 67.37, 6.25, 7.35.

EXAMPLE C3 (2S,4S)-4-Fluoro-1-[(2S,3S)-2-hydroxy-3-(3-hydroxy-2-methyl-benzoylamino)-4-phenyl-butyryl]-pyrrolidine-2-carboxylic acid 2-methyl-benzylamide

Isolated material was subjected to flash silica gel chromatography, eluting with EtOAc/hexanes (50/50) then with EtOAc to afford the title compound. ¹H NMR (400 MHz, DMSO-d₆): δ 9.37 (s, 1H), 8.21 (d, 1H), 7.96 (t, 1H), 7.29 (d, 2H), 7.23 (t, 2H), 7.18-7.13 (m, 2H), 7.10-7.04 (m, 3H), 6.90 (t, 1H), 6.75 (d, 1H), 6.52 (d, 1H), 5.55 (d, 1H), 5.45+5.32 (bs+bs, 1H), 4.54 (d, 1H), 4.42-4.36 (m, 1H), 4.29-4.40 (m, 5H), 2.98 (t, 1H), 2.73 (t, 1H), 2.32-2.21 (m, 2H), 2.19 (s, 3H), 1.78 (s, 3H); MS-APCI (m/z+): 548; HPLC: Rf (min.) 18.21; Purity: 99%; Anal. C₃₁H₃₄N₃O₅F.0.5H₂O calcd: 66.89, 6.34, 7.55, found: 66.85, 6.22, 7.41.

EXAMPLE C4 (S)-3-((2S,3S)-2-Hydroxy-3-{1′-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-oxazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.80 (dd, J=8.8,4.8, 1H), 8.30 (t, J=5.5, 1H), 8.12 (d, J=8.6, 1H), 7.30-7.13 (m, 9H), 6.96 (t, J=7.9, 1H), 6.76 (d, J=7.9, 1H), 6.55 (d, J=7.2, 1H), 5.74 (d, J=8.8, 1H), 5.31 (d, J=3.8, 1H), 5.23 (d, J=4.2, 1H), 4.49 (dd, J=6.6, 6.5, 1H), 4.33-4.11 (m, 5H), 2.94-2.68 (m, 2H), 2.24 (s, 3H), 1.78 (s, 3H); HRMS (ESI) m/z calcd for C₃₀H₃₄N₃O₆ (M+H)⁺ 532.2448, found 532.2450.

EXAMPLE C5 (4S,5R)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5-methyl-oxazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid; ¹HNMR (DMSO-d₆) δ9.38 (s, 1H), 8.51 (t, J=6.0, 1H), 8.15 (d, J=8.4, 1H), 7.33-7.13 (m, 9H), 6.96 (t, J=7.7, 1H), 6.79 (d, J=8.2, 1H), 6.58 (d, J=7.3, 1H), 5.69 (d, J=5.7, 1H), 5.50 (d, J=4.6, 1H), 5.10 (d, J=4.8, 1H), 4.39-4.22 (m, 4H), 4.11-4.01 (m, 2H), 2.90 (m, 1H), 2.74 (m, 1H), 227 (s, 3H), 1.82 (s, 3H), 1.37 (d, J=5.9, 1H); HRMS (ESI) m/z calcd for C₃₁H₃₆N₃O₆ (M+H)⁺ 546.2604, found 546.2595.

EXAMPLE C6 (S)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-oxazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid; ¹H NMR (DMSO-d₆) δ 9.34 (s, 1H), 8.32 (t, J=5.8, 1H), 8.11 (J=9.0, 1H), 7.31-7.10 (m, 9H), 6.93 (t, J=7.9, 1H), 6.76 (d, J=8.1, 1H), 6.55 (d, J=6.5, 1H), 5.73 (d, J=4.0, 1H), 5.46 (d, J=4.1, 1H), 5.23 (d, J=3.9, 1H), 4.39-4.32 (m, 2H), 4.18 (m, 3H), 2.92 (m, 1H), 2.69 (m, 1H), 2.27 (s, 3H), 1.81 (s, 3H), 1.28 (s, 3H), 1.18 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₈N₃O₆ (M+H)⁺ 560.2761, found 560.2759; Anal. Calcd for C₃₂H₃₇N₃O₆.0.5H₂O: C, 67.59; H, 6.74; N, 7.39. Found: C, 67.74; H, 6.75; N, 7.16.

EXAMPLE C7 (S)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-oxazolidine-4-carboxylic acid propylamide

¹H NMR (DMSO-d₆) δ 9.37 (s, 1H), 8.12 (d, J=9.3, 1H), 7.93 (t, J=5.6, 1H), 7.34-7.18 (m, 5H), 6.96 (t, J=8.1, 1H), 6.79 (d, J=8.1, 1H), 6.56 (d, J=7.1, 1H), 5.73 (d, J 6.2, 1H), 5.44 (d, J=4.0, 1H), 5.24 (d, J=3.8, 1H), 4.36 (m, 1H), 4.18 (m, 1H), 4.11 (s, 1H), 3.10-2.92 (m, 3H), 2.75-2.66 (m, 1H), 1.80 (s, 3H), 1.46-1.39 (m, 2H), 1.31 (s, 3H), 1.22 (s, 3H), 0.86 (t, J=7.2, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₆N₃O₆ (M+H)+498.2604, found 498.2590.

EXAMPLE C8 (4S,5S)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5-methyl-oxazolidine-4-carboxylic acid 2-methyl-benzylamide

White solid; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.26 (t, J=5.5, 1H), 8.09 (d, J=8.8, 1H), 7.30-7.08 (m, 9H), 6.93 (t, J=7.7, 1H), 6.76 (d, J=7.9, 1H), 6.56 (d, J=7.5, 1H), 5.72 (d, J=64, 1H), 5.55 (d, J=3.7, 1H), 5.08 (d, J=3.8, 1H), 4.40-4.33 (m, 3H), 4.26-4.11 (m, 3H), 3.10-2.89 (m, 1H), 2.78-2.67 (m, 1H), 2.26 (s, 3H), 1.78 (s, 3H), 1.15 (d, J=6.2, 3H); HRMS (ESI) m/z calcd for C₃₁H₃₆N₃O₆ (M+H)⁺ 546.2604, found 546.2592.

EXAMPLE C9 (S)-3-(2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-oxazolidine-4-carboxylic acid 5-fluoro-2-methyl-benzylamide

White solid; ¹H NMR (DMSO-d₆) δ 9.35 (s, 1H), 8.41 (t, J=5.6, 1H), 8.12 (d, J=8.9, 1H), 7.28-7.08 (m, 8H), 6.95-6.90 (m, 1H), 6.76 (d, J=8.1, 1H), 6.55 (d, J=7.2, 1H), 5.78 (d, J=6.1, 1H), 5.47 (d, J=3.8, 1H), 5.24 (d, J=3.8, 1H), 4.40-4.25 (m, 2H), 4.20-4.10 (m, 3H), 3.00-2.60 (m, 2H), 2.22 (s, 3H), 1.77 (s, 3H), 1.30 (s, 3H), 1.19 (s, 3H); Anal. Calcd for C₃₂H₃₆N₃O₆F: C, 66.54; H, 6.28; N, 7.27. Found: C, 66.37; H, 6.20; N, 7.21.

EXAMPLE C10 (S)-3-((2S,3S)-2-Hydroxy-3-{[1-(3-hydroxy-2-methyl-phenyl)-methanoyl]-amino}-4-phenyl-butanoyl)-5,5-dimethyl-oxazolidine-4-carboxylic acid cyanomethyl-amide

White solid; ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.72 (t, J=5.3, 1H), 8.11 (d, J=9.0, 1H), 7.29-7.16 (m, 5H), 6.94 (t, J=7.7, 1H), 6.76 (d, J=8.1, 1H), 6.50 (d, J=7.5, 1H), 5.85 (d, J=6.0, 1H), 5.49 (d, J=4.0, 1H), 5.23 (d, J=3.9, 1H), 4.35 (m, 1H), 4.18-4.12 (m, 3H), 4.11 (s, 1H), 2.92 (m, 1H), 2.70 (m, 1H), 1.76 (s, 3H), 1.29 (s, 3H), 1.19 (s, 3H); HRMS (ESI) m/z calcd for C₂₆H₃₁N₄O₆ (M+H)⁺ 495.2244, found 495.2239.

EXAMPLE C1 (S)-3-((2S,3S)-3-{[1-(3-Fluoro-2-methyl-phenyl)-methanoyl]-amino}-2-hydroxy-4-phenyl-butanoyl)-5,5-dimethyl-oxazolidine-4-carboxylic acid 2-methyl-benzylamide

¹H NMR (DMSO-d₆) δ 8.34 (m, 2H), 7.30-7.13 (m, 1H), 6.95 (d, J=7.1, 1H), 5.82 (d, J=6.4, 1H), 5.45 (d, J=3.9, 1H), 5.23 (d, J=4.0, 1H); 4.38-4.31 (m, 2H), 4.18-4.15 (m, 3H), 2.96 (m, 1H), 2.67 (m, 1H), 2.26 (s, 3H), 1.87 (s, 3H), 1.28 (s, 3H), 1.18 (s, 3H); HRMS (ESI) m/z calcd for C₃₂H₃₇N₃O₅F (M+H)⁺ 562.2717, found 562.2713.

The synthesis of compounds with the general structure 27 is as follows. The boc-protected thiazolidine carboxylic acid 1 is converted to amino-ketones 26 with requisite grignard reagents 25 in the presence of oxalyl chloride. Final compounds 27 are obtained by a DCC-mediated coupling of 26 and 4 followed by deprotection of the P2 phenol. Final compounds were purified either by flash chromatography or preparative HPLC.

Specific Method D

EXAMPLE D1 N-[(1S,2S)-1-Benzyl-3-((R)-5,5-dimethyl-4-pent-4-enoyl-thiazolidin-3-yl)-2-hydroxy-3-oxo-propyl]-3-hydroxy-2-methyl-benzamide

The title compound was prepared as follows. (R)-5,5-Dimethyl-thiazolidine-3,4-dicarboxylic acid 3-tert-butyl ester 1 (1.0 g, 3.80 mmol) was dissolved in benzene (10 mL) and cooled to 0° C. with magnetic stirring. Two drops of DMF were added followed by a drop wise addition of oxalyl chloride (0.33 mL, 3.80 mmol). When gas evolution ceased, the solution was concentrated to a yellow/red residue. The material was dissolved in dry THF (10 mL) and cooled to −78° C. with magnetic stirring. The grignard reagent, 3-butenylmagnesium bromide (7.7 mL, 3.80 mmol) was added dropwise over 10 min. The result was stirred at −78° C. for 1 h then at −55° C. for 30 min. The reaction was quenched at −55° C. with sat NH₄Cl soln. (3 mL) and then poured into H₂O (50 mL). The mixture was extracted with EtOAc (2×50 mL). The combined organics were washed with brine (1×100 mL), dried over Na₂SO₄, filtered, and concentrated. The result was the amino ketone 26 that was sufficiently pure to use in the subsequent step. The clear oil 26 (0.24 g, 1.15 mmol) was dissolved in EtOAc (10 mL). AMB-AHPBA 4 (0.40 g, 1.09 mmol) was added followed by HOBt (0.15 g, 1.09 mmol). The mixture was stirred at room temperature 1 h, then cooled to 0° C. DCC (0.24 g, 1.15 mmol) was slowly added as solution in EtOAc (6 mL). The mixture was warmed to room temperature and stirred overnight. The mixture was filtered and the filtrate was washed with 1N HCl (10 mL), saturated NaHCO₃ (10 mL), brine (10 mL), dried over Na₂SO₄ and concentrated to give a crude white solid (contaminated with DCU). The DCU was removed by flash chromatography (30% to 50% EtOAc in hexanes) to provide a white solid, which was dissolved in MeOH (2 mL) and treated with 4N HCl in 1,4-dioxane (0.26 mL, 1.1 mmol). The reaction was stirred at room temperature overnight then partitioned between 1N HCl (10 mL) and EtOAc (10 mL). The organic layer was washed with saturated sat. NaHCO₃ (1×25 mL) dried over Na₂SO₄, filtered, and concentrated to a residue which was purified by flash chromatography (60% EtOAc in hexanes) to provide the title compound as a white amorphous solid: ¹H NMR (DMSO-d₆) δ 9.36 (s, 1H), 8.23 (d, J=8.1, 1H), 7.35-7.14 (m, 5H), 6.96 (t, J=7.5, 1H), 6.78 (d, J=8.2, 1H), 6.52 (d, J=7.5, 1H), 5.81-5.69 (m. 2H), 5.32 (d, J=9.7, 1H), 5.11-5.91 (m, 3H), 4.40 (m, 3H), 2.89-2.61 (m, 4H), 2.37-2.14 (m, 2H), 1.81 (s, 3H), 1.55 (s, 3H), 1.30 (s, 3H); Anal. Calcd for C₂₈H₃₄N₂O₅S: C, 65.86; H, 6.71; N, 5.49. Found: C, 65.52; H, 6.55; N, 5.81.

The following examples were synthesized using the specific method outlined above using the appropriate grignard reagent for the desired compound.

EXAMPLE D2 N-{1-Benzyl-3-[5,5-dimethyl-4-(4,4,4-trifluoro-butanoyl)-thiazolidin-3-yl]-2-hydroxy-3-oxo-propyl}-3-hydroxy-2-methyl-benzamide

¹H NMR (DMSO-d₆) δ 9.34 (s, 1H), 8.16 (d, 1H, J=8.6), 7.29-6.49 (m, 8H), 5.88 (d, 1H, J=6.1), 5.33 (d, 1H, J=9.5), 5.10 (d, 1H, J=9.5), 4.56 (s br, 3H), 2.98-2.57 (m, 6H), 1.74 (s, 3H), 1.55 (s, 3H), 1.30 (s, 3H); HRMS (ESI) m/z calcd for C₂₇H₃₂N₂O₅SF₃ (M+H)⁺ 553.1984, found 553.1984; Anal. Calcd for C₂₇H₃₁N₂O₅SF₃.0.5H₂O: C, 58.59; H, 5.66; N, 5.06; S, 5.79. Found: C, 58.96; H, 6.02; N, 5.58; S, 5.33.

EXAMPLE D3 N-{1-Benzyl-2-hydroxy-3-[4-(4-methoxy-butanoyl)-5,5-dimethyl-thiazolidin-3-yl]-3-oxo-propyl}-3-hydroxy-2-methyl-benzamide

¹H NMR (DMSO-d₆) δ 9.34 (s, 1H), 8.18 (d, 1H, J=8.2), 7.32-6.51 (m, 8H), 5.56 (d, 1H, J=7.8), 5.26 (d, 1H, J=9.5), 5.08 (d, 1H, J=9.5), 4.45-4.38 (m, 2H), 4.36 (s, 1H), 3.15 (s, 3H), 2.93-2.61 (m, 2H), 1.87-1.00 (m, 6H), 1.80 (s, 3H), 1.55 (s, 3H), 1.36 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₇N₂O₆S (M+H)⁺ 529.2165, found 529.2372;

Anal. Calcd for C₂₈H₃₆N₂O₆S. 0.5 H₂O: C, 62.55; H, 6.94; N, 5.21; S, 5.96. Found: C, 62.89; H, 7.32; N, 5.96; S, 5.59.

EXAMPLE D4 (R)-3-[(2S,3S)-2-Hydroxy-3-(3-hydroxy-2,5-dimethyl-benzoylamino)-4-phenyl-butyryl]-5,5-dimethyl-thiazolidine-4-carboxylic acid allylamide

White solid: ¹H NMR (DMSO-d₆) δ 9.23 (s, 1H), 8.09 (m, 2H), 7.35-7.17 (m, 5H), 6.60 (s, 1H), 6.37 (s, 1H), 5.82-5.68 (m, 1H), 5.41 (br s, 1H), 5.20 (dd, 1H, J=1.6, 17.2), 5.11 (d, 1H, J=9.2), 5.02 (dd, 1H, J=1.5, 10.2), 5.00 (d, 1H, J=9.1), 4.46-4.37 (m, 3H), 3.79 (ddd, 1H, J=5.3,5.5, 15.9), 3.63 (ddd, 1H, J=5.4, 5.3, 15.9), 2.82 (dd, 1H, J=0.3, 13.9), 2.71 (dd, 1H, J=10.7, 13.6), 2.16 (s, 3H), 1.76 (s, 3H), 1.51 (s, 3H), 1.36 (s, 3H); HRMS (ESI) m/z calcd for C₂₈H₃₆N₃O₅S (M+H)⁺ 526.6670, found 526.2376; Anal. Calcd for C₂₈H₃₅N₃O₅S 0.3H₂O: C, 63.32; H, 6.76; N, 7.91, Found: C, 63.35; H, 6.70; N, 7.71. Combinatorial Chemistry Approach to HIV Protease P2′ Inhibitors

The combinatorial building block, 8, is prepared using the following method. The boc-protected thiazolidine carboxylic acid, 1, is treated with allyl bromide in the presence of NaHCO₃ to yield the boc-protected thiazolidine allyl ester, 2. Deprotection of boc-protected allyl ester, 2, with HCl (g) in EtOAc gives the HCl salt of the thiazolidine allyl ester amine, 3, which is treated with TEA and coupled to 4 in the presence of HOBT and DCC to give the building block precursor, 5. Deprotection of the building block, 5, with 4N HCl yields the phenol, 6. Loading the building block, 6, on to activated cross-linked trityl chloride polystyrene beads, 7, was accomplished in the following manner. The polystyrene cross-linked trityl alcohol was activated to the trityl chloride, 7, by treatment with 20% acetyl chloride in anhydrous CH₂Cl₂ at room temperature. The trityl chloride beads were combined with the phenol 6 in the presence of Hunig's base in anhydrous CH₂Cl₂ to yield the substrate loaded polystyrene beads 8. Intermediates were purified either by flash chromatography or preparative HPLC.

The synthesis of the HIV protease combinatorial library was carried out in the following fashion. The allyl ester was removed by treatment with Pd[PPh₃]₄ and NMM in anhydrous THF to give carboxylate 9, which was treated with pentafluorophenol, pentafluorophenol trifluoromethyl acetate and pyridine in DMF to yield the pentafluoro ester, 10. The pentafluoro ester 10 was treated with various primary amines in a 96-well plate format to give amides 12. The final products were cleaved from the polystyrene crowns with TFA to give products 13. Each product was analyzed by LCMS and HPLC. The following table typifies compounds synthesized by this combinatorial method. TABLE 1 Expected Mass Observed % P2′ (LCMS) Mass Inhibition

529 552(Na⁺) 38

528 529(MH⁺) 4

591 614(Na⁺) 18

555 578(Na⁺) 19

635 658(Na⁺) 5

656 656(MH⁺) 8

575 598(Na⁺) 86

541 564(Na⁺) 63

529 552(Na⁺) 49

The solid phase combinatorial synthesis of HIV protease inhibitors was performed using the IRORI Directed Sorting Technology. Commercial 4-formyl-3-methoxyphenoxymethyl polystyrene resin 1a (PS-MB-CHO, Argonaut Technologies) or 4-formyl-3,5-dimethoxyphenoxymethyl polystyrene resin 1b (PL-FDMP resin, Polymer Laboratories) was loaded into individual Minikans.

Step A. Reductive Amination with P_(2′) Amines

To separate flasks containing sorted MiniKans was added DCM (3 mL/MiniKan). The appropriate primary P₂′ amine (3 eq), sodium triacetoxyborohydride (5 eq), and acetic acid (3 eq) were added, and the mixtures were placed under argon, agitated with periodic venting at room temperature for 1-2 hours, and allowed to react overnight. For resin 1a, the filtrates were poured off and the MiniKans were washed with DCM, MeOH (2×), DCM (2×), Et₃N/DCM (1:3, 3×), DCM (2×), MeOH (3×), and DCM (4×). For resin 1b, a washing sequence of DCM, MeOH (2×), DCM (2×), Et₃N/DCM (1:3, 3×), DCM (2×), DMF, 1M NaOH/DMF (1:5, 3×), DMF (3×), MeOH (3×), and DCM (3×) was used. The MiniKans were dried under vacuum and taken on in Step B.

Step B. Peptide Coupling with P_(1′) Amino Acids

To separate flasks containing the sorted MiniKans was added DMF (3 mL/MiniKan). The appropriate FMOC-protected amino acid (2.5 eq) and 1-hydroxy-7-azabenzotriazole (HOAT) (3 eq) were added and mixed until dissolved, and 1,3-diisopropylcarbodiimide (DIC) (3 eq) was added. The containers were placed under argon and agitated at room temperature overnight. The filtrates were poured off, and the MiniKans were washed with DMF (3×), MeOH (3×), DCM (2×), and DMF (2×). The MiniKans were taken directly on to Step C.

Step C. FMOC Deprotection

A container of MiniKans in DMF and piperidine (25%) with a total reaction volume of 3 mL/MiniKan was agitated under argon at room temperature for 45 minutes. The filtrate was removed, and the reaction procedure was repeated. The MiniKans were filtered and washed with DMF (3×), MeOH (2×), DCM (3×), and DMF, and taken directly on to Step D.

Step D. Peptide Coupling with FMOC-APNS

FMOC-Allophenylnorstatine (APNS) (3 eq) was added to the flask of MiniKans in DMF (3 mL/MiniKan). After dissolution, HOAT (3.5 eq) and DIC (3.5 eq) were added. The mixture was placed under argon and agitated at room temperature overnight. The reaction was filtered and the MiniKans were washed with DMF (3×), MeOH (3×), DCM (3×), and DMF. FMOC deprotection was carried out as in Step C, and the MiniKans were washed with DMF (3×), MeOH (2×), DCM (3×), dried under vacuum and taken on to Step E or F.

Step E. Peptide Coupling with P₂ Acids

To separate flasks containing the sorted MiniKans in DMF (3 mL/MiniKan) was added the appropriate P₂ acid (3 eq), HOBT hydrate (4 eq), and (3-(dimethylamino)propyl)ethylcarbodiimide hydrochloride (EDAC) (3.5 eq). The reaction was agitated under argon at room temperature for 3 hours. After filtration, the MiniKans were washed with DMF (3×), MeOH (3×), and DCM (3×), dried under vacuum, and taken on to Step G.

Step F. Cleavage and Processing of the HIV Analogs

The individual MinKans were sorted into cleavage racks and a solution of 25% TFA in DCM (3 mL/MinKan) was added. The racks were agitated for 1.5 hours. The individual filtrates and DCM rinses were collected, concentrated, and purified by HPLC to provide the final compounds. TABLE 2

Scheme 3 Experimental

The solid phase combinatorial synthesis of HIV protease inhibitors was performed using the IRORI Directed Sorting Technology. Commercial 4-formyl-3-methoxyphenoxymethyl polystyrene resin 1a (PS-MB-CHO, Argonaut Technologies) or 4-formyl-3,5-dimethoxyphenoxymethyl polystyrene resin lb (PL-FDMP resin, Polymer Laboratories) was loaded into individual Minikans.

Step A. Reductive Amination with P_(2′) Amines

To separate flasks containing sorted MiniKans was added DCM (3 mL/MiniKan). The appropriate primary P₂′ amine (3 eq), sodium triacetoxyborohydride (5 eq), and acetic acid (3 eq) were added, and the mixtures were placed under argon, agitated with periodic venting at room temperature for 1-2 hours, and allowed to react overnight. For resin 1a, the filtrates were poured off and the MiniKans were washed with DCM, MeOH (2×), DCM (2×), Et₃N/DCM (1:3, 3×), DCM (2×), MeOH (3×), and DCM (4×). For resin 1b, a washing sequence of DCM, MeOH (2×), DCM (2×), Et₃N/DCM (1:3, 3×), DCM (2×), DMF, 1M NaOH/DMF (1:5, 3×), DMF (3×), MeOH (3×), and DCM (3×) was used. The MiniKans were dried under vacuum and taken on in Step B.

Step B. Peptide Coupling with P_(1′) Amino Acids

To separate flasks containing the sorted MiniKans was added DMF (3 mL/MiniKan). The appropriate FMOC-protected amino acid (2.5 eq) and 1-hydroxy-7-azabenzotriazole (HOAT) (3 eq) were added and mixed until dissolved, and 1,3-diisopropylcarbodiimide (DIC) (3 eq) was added. The containers were placed under argon and agitated at room temperature overnight. The filtrates were poured off, and the MiniKans were washed with DMF (3×), MeOH (3×), DCM (2×), and DMF (2×). The MiniKans were taken directly on to Step C.

Step C. FMOC Deprotection

A container of MiniKans in DMF and piperidine (25%) with a total reaction volume of 3 mL/MiniKan was agitated under argon at room temperature for 45 minutes. The filtrate was removed, and the reaction procedure was repeated. The MiniKans were filtered and washed with DMF (3×), MeOH (2×), DCM (3×), and DMF, and taken directly on to Step D.

Step D. Peptide Coupling with FMOC-APNS

FMOC-Allophenylnorstatine (APNS) (3 eq) was added to the flask of MiniKans in DMF (3 mL/MiniKan). After dissolution, HOAT (3.5 eq) and DIC (3.5 eq) were added. The mixture was placed under argon and agitated at room temperature overnight. The reaction was filtered and the MiniKans were washed with DMF (3×), MeOH (3×), DCM (3×), and DMF. FMOC deprotection was carried out as in Step C, and the MiniKans were washed with DMF (3×), MeOH (2×), DCM (3×), dried under vacuum and taken on to Step E or F.

Step E. Peptide Coupling with P₂ Acids

To separate flasks containing the sorted MiniKans in DMF (3 mL/MiniKan) was added the appropriate P₂ acid (3 eq), HOBT hydrate (4 eq), and (3-(dimethylamino)propyl)ethylcarbodiimide hydrochloride (EDAC) (3.5 eq). The reaction was agitated under argon at room temperature for 3 hours. After filtration, the MiniKans were washed with DMF (3×), MeOH (3×), and DCM (3×), dried under vacuum, and taken on to Step G.

Step F. Cleavage and Processing of the HIV Analogs

The individual MinKans were sorted into cleavage racks and a solution of 25% TFA in DCM (3 mL/MinKan) was added. The racks were agitated for 1.5 hours. The individual filtrates and DCM rinses were collected, concentrated, and purified by HPLC to provide the final compounds. TABLE 3

Biological Evaluation

Cells and Virus

T-cell lines, CEM-SS, and MT-2, and viruses HIV-1 RF and HIV-1 NL4-3 (pNL4-3) were obtained from the National Institutes of Health (AIDS Research and Reference Reagent Program, Bethesda, Md.). HIV-1 NL4-3(184V/L90M) was derived from a clinical isolate that exhibited the protease inhibitor-resistance associated substitutions 184V and L90M, by cloning of an reverse transcriptase-polymerase chain reaction amplified fragment into the unique Age I and Spe I restriction sites of pNL4-3.

Cytopathic Effect (CPE) Inhibition Assays

The ability of compounds to protect cells against HIV infection was measured by the MTT dye reduction method, essentially as described (See Pauwels, R. Balzarini, J. Baba, M. Snoeck, R. Schols, D. Herdewijn, P. Desmyter, J. and De Clercq, E. 1988, “Rapid and automated tetrazolium-based calorimetric assay for the detection of anti-HIV compounds,”. J. Virol. Methods., 20: 309-321 and Weislow, O. S. Kiser, R. Fine, D. L. Bader, J. Shoemaker, R. H. and Boyd, M. R. 1989. “New soluble-formazan assay for HIV-1 cytopathic effects: application to high-flux screening of synthetic and natural products for AIDS-antiviral activity”. J. Natl. Cancer Inst. 81:577-586). Subject cells were infected with test virus at an moi of 0.025 to 0.819 or mock infected with medium only and added at 2×10⁴ cells per well into 96 well plates containing half-log dilutions of test compounds. Six days later, 50 μl of XTT (]mg/ml XTT tetrazolium, 0.02 nM phenazine methosulfate) was added to the wells and the plate was reincubated for four hours. Viability, as determined by the amount of XTT formazan produced, was quantified spectrophotometrically by absorbance at 450 nm. Data from CPE assays were expressed as the percent of formazan produced in compound-treated cells compared to formazan produced in wells of uninfected, compound-free cells. The fifty percent effective concentration (EC₅₀) was calculated as the concentration of compound that effected an increase in the percentage of formazan production in infected, compound-treated cells to 50% of that produced by uninfected, compound-free cells. The 50% cytotoxicity concentration (CC₅₀) was calculated as the concentration of compound that decreased the percentage of formazan produced in uninfected, compound-treated cells to 50% of that produced in uninfected, compound-free cells. The therapeutic index was calculated by dividing the cytotoxicity (CC₅₀) by the antiviral activity (EC₅₀).

Susceptibility Assays

Compounds were tested in phenotypic susceptibility assays at Virologic, Inc., (See Petropoulos C. J., Parkin N. T., Limoli K. L., Lie Y. S., Wrin T., Huang W., Tian H., Smith D., Winslow G. A., Capon D J, Whitcomb JM. 2000, “A novel phenotypic drug susceptibility assay for human immunodeficiency virus type 1,” Antimicrob Agents Chemother 44(4):920-928) or using the assay described here. MT-2 cells were infected with either HIV-1 NL4-3 or HIV-1 NL4-3(184V/L90M) and incubated in the presence of serial 0.5 log dilutions of test compounds. Three days later, culture supernatants were collected and virus production, as determined by p24 ELISA, was assayed. Percent inhibition was calculated as p24 concentration in compound-treated samples as compared to infected, compound-free controls. Inhibition of viral replication is determined by measuring reduction in HIV p24 present in the culture supernatant, using a Beckman-Coulter p24 HIV-1 Ag EIA kit and following the supplied protocol. Absorbance is read on a MRX microplate reader (Dynex Technologies). The EC₅₀ was calculated as the concentration of compound that effected a decrease in the p24 production by infected, compound-treated cells to 50% of that produced by infected, compound-free cells.

HIV-1 Protease RET Assay

Ki's for the inhibitors of HIV-1 protease were determined using a resonance energy transfer (RET) assay. A mutant form of this enzyme (Q7S) is used for this assay because it is more stable against auto-proteolysis than the wild-type protein. This enzyme is first partially purified as inclusion bodies from cell lysate. It is then solublized in 8M urea and passed through a Q-Sepharose column (Pharmacia) for further purification. To refold this protein, samples containing Q7S is dialyzed into 50 mM sodium phosphate pH 7.0, 50 mM NaCl, 10 mM DTT, and 10% glycerol.

The commercially available peptide substrate (Molecular Probes Cat. # H-2930) RE(EDANS)SQNYPIVQK(DABCYL)R is used to assess activity and Ki's. This peptide is cleaved quantitatively by HIV-1 Pr at the Tyr-Pro bond. The EDANS fluorophore absorbs at 340 nm and emits at 490 nm. The reaction is carried out in a 96 well plate in a total volume of 100 μL and is run for 12 minutes at 37 C under steady-state conditions with 5 μM substrate and 2 nM active dimer enzyme concentration. The literature value Km for this substrate and enzyme is 103+/−8 μM (See Matayoshi, et al., “Novel Fluorogenic Substrates for Assaying Retroviral Proteases by Resonance Energy Transfer,” Science 247, 954 (1990)). The buffer for this reaction is 0.1M sodium acetate pH 4.8, 1M NaCl, 1 mM EDTA, 5 mM dithiothreitol, 10% dimethyl sulfoxide and 1 mg/ml bovine serum albumin. Inhibition curves are fit using the Morrison tight binding equation. Example Ave. Ave CPE EC₅₀ or No. K_(i) (nM) EC₅₀ (mM) IC₅₀ (mM) A3 1.7 0.37 A4 4.1 0.591 A5 2 0.433 A6 0.22 0.036 A7 0.49 0.104 0.832 A8 0.23 0.036 A9 4 0.565 A10 51 >1 A11 19 0.93 A12 1.7 1.09 A13 44.1 >1 A14 0.44 0.052 0.071* A15 10.9 0.13 A16 0.63 0.134 A17 <0.1 0.045 0.102* A18 0.38 0.193 A19 10 0.442 A20 0.13 0.037 0.147* A21 1.9 0.717 A22 0.32 0.061 0.226* A23 0.65 0.072 A24 0.18 0.104 0.831 A25 5.8 0.248 A26 0.38 0.119 0.321* A27 0.62 0.072 A28 <0.1 0.041 A29 <0.1 0.117 A30 1.1 0.507 0.829* A31 <0.1 0.041 A32 <0.1 0.045 0.486 A33 <0.1 0.577 A34 <0.1 0.036 A35 <0.1 0.017 0.063 A36 0.59 0.519 A37 0.13 0.161 A38 0.17 0.078 0.401 A39 0.27 0.367 A40 1.2 0.275 A41 1.6 0.527 A42 0.23 0.126 0.307 A43 0.35 0.561 A44 0.14 0.022 0.472 A45 0.51 0.165 A46 0.31 0.091 0.79 A47 2.3 1.813 A48 0.19 0.417 A49 1.2 0.13 A50 0.26 0.224 A51 1.3 0.667 A52 37 B1 2.5 0.905 B2 0.78 0.369 B3 4 0.409 B8 0.31 0.095 0.405* B4 1.7 0.551 B5 1.6 0.508 B6 1.6 0.589 B7 1.9 0.68 B8 1.5 0.552 B10 <0.1 1.1 B11 1.2 1.175 1.716* B12 0.45 1.398 B13 19% @64 nM B14 3.7 3.054 B15 2 1.086 B16 <0.1 0.298 1.754 B17 0.42 0.534 1.579 B18 0.29 0.457 B19 <0.1 0.124 1.369 B20 2.1 0.427 B21 4.6 0.598 B22 1.8 1.613 B23 0.42 1.42 B24 5.5 2.136 B25 2.7 1.794 B26 2.9 1.712 B27 3.5 B28 153 B29 0.12 1.256 B30 1.1 1.227 B31 1.5 1.316 B32 4.9 B33 1.2 1.286 B34 B35 B36 <0.1 0.615 B37 0.11 0.736 B38 B39 0.16 B40 2.8 1.396 B41 0.15 B42 0.73 B43 0.2 B44 0.76 0.629 B45 19.7 B46 12.5 B47 6.9 B48 12 >3.2 B49 17.2 C1 0.38 0.627 0.427 C3 1.3 0.5 C4 4.2 C4 69 C5 3.2 C6 <0.1 0.164 1.475 C7 7.9 C8 0.26 0.447 C9 0.34 0.233 C10 36 C11 1.1 1.562 D1 <0.01 0.052 0.601 D3 0.5 0.162 1.954 D4 0.7 0.016 1.954 *IC₅₀ (mM) Data was determined at Virologic Inc against the 46I, 84V, 90M virus

The following compounds have been prepared according to the procedures described herein and have demonstrated the noted activity: MOLSTRUCTURE K_(i) EC₅₀

209 10

1700 10

0.1 0.053

62

0.75

0.1 0.072

1.5 0.076

0.2 0.113

0.73 0.141

0.36 0.144

0.24 0.158

0.26 0.207

0.17 0.289

0.11 0.334

0.2 0.585

9.6 0.723

4.7 1.064

1.1 1.114

2.5 1.221

7.4

2.6 1.3095

2.6 1.3095

3.4

3.7 1.332

72

2.3 1.378

11.1 1.401

2.6 1.416

2.1 1.488

14 1.512

18.5

19.5 3

12.1

10.5 3.2

17.3 3.303

16.8 3.745

13.1

0.1

28 4.132

0.1

24.6 4.951

55.8 10

214 10

The following compounds have been prepared according to the procedures described herein and have demonstrated the noted activity:

While the invention has been described in terms of preferred embodiments and specific examples, those skilled in the art will recognize that various changes and modifications can be made through routine experimentation without departing from the spirit and scope of the invention. Thus, the invention should be understood as not being limited by the foregoing detailed description, but as being defined by the appended claims and their equivalents. 

1-19. (canceled)
 20. A compound having the Formula I:

wherein: R¹ is a 5- or 6-membered mono-cyclic carbocyclic or heterocyclic group, wherein said carbocyclic or heterocyclic group is saturated, partially unsaturated or fully unsaturated and is unsubstituted or substituted by one or more suitable substituents; R² is a substituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted phenyl group, a substituted phenylalkyl group, a substituted or unsubstituted phenylalkenyl group or a substituted or unsubstituted phenylalkynyl group, R^(2′) is H or a substituted or unsubstituted C₁-C₄ alkyl group; X is

 wherein R^(x) is H or one or more suitable substituents; Z is CH₂ or CFH; R³ is H or a substituted or unsubstituted C₁-C₄ alkyl group; R⁴, R⁵, R⁶ and R⁷ are independently selected from H or a C₁-C₆ alkyl group; and R⁸ and R^(8′) are independently selected from H, halo, a C₁-C₄ aliphatic group or a C₁-C₄ halo-substituted aliphatic group; where any of said substituted alkyl, alkenyl or alkynyl groups or said alkyl, alkenyl or are substituted by one or more suitable substituents; provided that said 5- or 6-membered mono-cyclic heterocycloalkyl, heterocycloalkenyl or heteroaryl group contains at least two heteroatoms when R² is a substituted phenyl group, a substituted phenylalkyl group, a substituted or unsubstituted phenylalkenyl group or a substituted or unsubstituted phenylalkynyl group; or provided that said alkyl, alkenyl or alkynyl moiety of said substituted phenylalkyl, phenylalkenyl or phenylalkynyl group is substituted by one or more substituents selected from halo or keto; or provided that said substituted phenyl group or phenyl moiety of said substituted phenylalkyl, phenylalkenyl or phenylalkynyl group is substituted by one or more suitable substituents other than halo or methyl; or a prodrug, pharmaceutically acceptable salt, pharmaceutically active metabolite, or pharmaceutically acceptable solvate thereof.
 21. A compound having the Formula I:

wherein: R¹ is a 5- or 6-membered monocyclic cycloalkyl, cycloalkenyl, aryl, heterocycloalkyl, heterocycloalkenyl or heteroaryl group, where said cycloalkyl, cycloalkenyl, aryl, heterocycloalkyl, heterocycloalkenyl or heteroaryl group is unsubstituted or substituted with one or more substituents independently selected from alkyl, haloalkyl, amino, cyano, halogen, hydroxyl, alkoxy, haloalkoxy, alkylenedioxy, di-haloalkylenedioxy, aryloxy, cycloalkoxy, cycloalkylalkoxy, cycloalkenoxy, cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy, heterocycloalkenyloxy, heterocycloalkenylalkoxy, heteroaryloxy, alkylcarbonyloxy, arylcarbonyloxy, heteroarylcarbonyloxy, alkylamino, dialkylamino, keto, alkylsulfonyl, arylsulfonyl, alkylcarbonylamino, alkylthio, haloalkylthio and arylthio, wherein any of the alkyl, alkylene, aryl, cycloalkyl, heterocycloalkyl, heteroaryl moieties present in the above substituents are further substituted by one or more groups independently selected from alkyl, haloalkyl, aryl, nitro, amino, alkylamino, dialkylamino, halogen, hydroxyl, alkoxy, haloalkoxy, aryloxy, mercapto, alkylthio, haloalkylthio and arylthio groups; R² is a substituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted alkynyl group, wherein said alkyl, alkenyl or alkynyl group is a straight or branched chained group, and where said substituted alkyl, alkenyl or alkynyl group is substituted by one or more substituents independently selected from amino, cyano, halogen, hydroxyl, alkoxy, haloalkoxy, aryloxy, cycloalkoxy, cycloalkylalkoxy, cycloalkenyloxy, cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy, heterocycloalkenyloxy, heterocycloalkenylalkoxy, heteroaryloxy, alkylamino, dialkylamino, alkylsulfonyl, arylsulfonyl, alkylsulfenyl, arylsulfenyl, alkylthio, haloalkylthio, arylthio and heteroarylthio groups, wherein any of the alkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, or heteroaryl moieties present in the above substituents are further substituted by one or more groups independently selected from alkyl, haloalkyl, halogen, hydroxyl, alkoxy, haloalkoxy, alkylthio and haloalkylthio groups; R^(2′) is H, methyl, ethyl or propyl, where said methyl, ethyl or propyl is unsubstituted or substituted by halo or hydroxyl; X is

 wherein R^(x) is H or one or more substituents independently selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, hydroxyl, alkylenedioxy, di-haloalkylenedioxy, alkylamino, dialkylamino, alkylthio and haloalkylthio; Z is CH₂ or CFH; R³ is H; R⁴, R¹, R⁶ and R⁷ are independently selected from H or methyl; and R⁸ and R^(8′) are independently selected from H, halogen, methyl, monohalo-methyl, dihalo-methyl and tri-halomethyl; or a prodrug, pharmaceutically active metabolite or pharmaceutically active salt or solvate thereof.
 22. The compound according to claim 21, wherein: R¹ is phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl, tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl, where said phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl, tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl is unsubstituted or substituted with one or more substituents independently selected from alkyl, haloalkyl, halogen, and hydroxyl; R² is a substituted alkyl group, a substituted or unsubstituted C₁-C₆ alkenyl group, or a substituted or unsubstituted C₁-C₆ alkynyl group, wherein said alkyl, alkenyl or alkynyl group is a straight or branched chained group, and where said substituted alkyl, alkenyl or alkynyl group is substituted by one or more substituents independently selected from cyano, halogen and alkylamino; R^(2′) is H, methyl or ethyl; X is

 wherein R^(x) is H, halogen, or alkoxy; Z is CH₂ or CFH; R³, R⁴, R⁵, R⁸ and R^(8′) are each H; and R⁶ and R⁷ are independently selected from H or methyl; or a prodrug, pharmaceutically active metabolite or pharmaceutically active salt or solvate thereof.
 23. A compound having the Formula I:

wherein: R¹ is a 5- or 6-membered mono-cyclic cycloalkyl, cycloalkenyl, aryl, heterocycloalkyl, heterocycloalkenyl or heteroaryl group, where said cycloalkyl, cycloalkenyl, aryl, heterocycloalkyl, heterocycloalkenyl or heteroaryl group is unsubstituted or substituted with one or more substituents independently selected from alkyl, haloalkyl, amino, cyano, halogen, hydroxyl, alkoxy, haloalkoxy, alkylenedioxy, dihaloalkylenedioxy, aryloxy, cycloalkyloxy, cycloalkylalkoxy, cycloalkenyloxy, cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy, heterocycloalkenyloxy, heterocycloalkenylalkoxy, heteroaryloxy, alkylcarbonyloxy, arylcarbonyloxy, heteroarylcarbonyloxy, alkylamino, dialkylamino, kato, alkylsulfonyl, arylsulfonyl, alkylcarbonylamino, alkylthio, haloalkylthio and arylthio, wherein any of the alkyl, alkylene, aryl, cycloalkyl, heterocycloalkyl, heteroaryl moieties present in the above substituents are substituted by one or more groups independently selected from alkyl, haloalkyl, aryl, nitro, amino, alkylamino, dialkylamino, halogen, hydroxyl, alkoxy, haloalkoxy, aryloxy, mercapto, alkylthio, haloalkylthio and arylthio groups; R² is a substituted phenyl group, a substituted phenylalkyl group, a substituted or unsubstituted phenylalkenyl group or a substituted or unsubstituted phenylalkynyl group; where said alkyl, alkenyl or alkynyl moiety of said phenylalkyl, phenylalkenyl or phenylalkynyl group is a straight or branched chain moiety; R^(2′) is H, methyl, ethyl or propyl, where said methyl, ethyl or propyl is unsubstituted or substituted with halo or hydroxyl; X is

 wherein R^(x) is H or one or more substituents independently selected from halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, hydroxyl, alkylenedioxy, di-haloalkylenedioxy, alkylamino, dialkylamino, alkylthio and haloalkylthio; Z is CH₂ or CFH; R³ is H; R⁴, R⁵, R⁶ and R⁷ are independently selected from H or methyl; and R⁸ and R^(8′) are independently selected from H, halogen, methyl, monohalo-methyl, dihalo-methyl and tri-halomethyl; provided that said 5- or 6-membered mono-cyclic heterocycloalkyl, heterocycloalkenyl or heteroaryl group contains at least two heteroatoms; or provided that said alkyl, alkenyl or alkynyl moiety of said substituted phenylalkyl, phenylalkenyl or phenylalkynyl group is substituted by one or more substituents selected from halo or keto; or provided that said substituted phenyl group or phenyl moiety of said substituted phenylalkyl, phenylalkenyl or phenylalkynyl group is substituted by one or more substituents other than halo or methyl, where said one or more substituents is independently selected from haloalkyl, hydroxyalkyl, alkoxyalkyl, cycloalkoxyalkyl, alkylcarbonylalkyl, haloalkoxyalkyl, aryloxyalkyl, alkylthioalkyl, haloalkylthioalkyl, arylthioalkyl, cyanoalkyl, aminoalkyl, alkylaminoalkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, heteroaryl, nitro, amino, cyano, hydroxyl, alkoxy, haloalkoxy, alkenyloxy, alkynyloxy, alkylenedioxy, aryloxy, cycloalkoxy, cycloalkylalkoxy, cycloalkenyloxy, cycloalkenylalkoxy, heterocycloalkoxy, heterocycloalkylalkoxy, heterocycloalkenyloxy, heterocycloalkenylalkoxy, heteroaryloxy, alkylcarbonyl, alkyloxycarbonyl, alkylcarbonyloxy, arylcarbonyl, arylcarbonyloxy, aryloxycarbonyl, cycloalkylcarbonyl, cycloalkylcarbonyloxy, cycloalkyoxycarbonyl, heteroarylcarbonyl, heteroarylcarbonyloxy, heteroaryloxycarbonyl, heterocycloalkylcarbonyl, heterocycloalkylcarbonyloxy, heterocycloalkyoxycarbonyl, carboxyl, carbamoyl, formyl, keto, thioketo, sulfo, alkylamino, cycloalkylamino, arylamino, heterocycloalkylamino, heteroarylamino, dialkylamino, alkylaminocarbonyl, cycloalkylaminocarbonyl, arylaminocarbonyl, heterocycloalkylaminocarbonyl, heteroarylaminocarbonyl, dialkylaminocarbonyl, alkylaminothiocarbonyl, cycloalkylaminothiocarbonyl, arylaminothiocarbonyl, heterocycloalkylaminothiocarbonyl, heteroarylaminothiocarbonyl, dialkylaminothiocarbonyl, alkylsulfonyl, arylsulfonyl, alkylsulfenyl, arylsulfenyl, alkylcarbonylamino, cycloalkylcarbonylamino, arylcarbonylamino, heterocycloalkylcarbonylamino, heteroarylcarbonylamino, alkylthiocarbonylamino, cycloalkylthiocarbonylamino, arylthiocarbonylamino, heterocycloalkylthiocarbonylamino, heteroarylthiocarbonylamino, alkylsulfonyloxy, arylsulfonyloxy, alkylsulfonylamino, arylsulfonylamino, mercapto, alkylthio, haloalkylthio, arylthio and heteroarylthio groups, wherein any of the alkyl, alkylene, aryl, cycloalkyl, heterocycloalkyl, or heteroaryl moieties present in the above substituents are unsubstituted or substituted by one or more groups independently selected from alkyl, haloalkyl, halogen, hydroxyl, alkoxy, haloalkoxy, alkylthio and haloalkylthio groups; or a prodrug, pharmaceutically active metabolite or pharmaceutically active salt or solvate thereof.
 24. The compound according to claim 23, wherein: R¹ is phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl, tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl, where said phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl, tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl is unsubstituted or substituted with one or more substituents independently selected from alkyl, haloalkyl, halogen, and hydroxyl; R² is a substituted phenylalkyl group, where said alkyl moiety of said substituted phenylalkyl group is a straight or branched chain alkyl moiety; R^(2′) is H, methyl, ethyl or propyl, where said methyl, ethyl or propyl is unsubstituted or substituted with hydroxyl; X is

 wherein R^(x) is H, halogen, or alkoxy; Z is CH₂ or CFH; R³, R⁴, R⁵, R⁸ and R^(8′) are each H; and R⁶ and R⁷ are independently selected from H or methyl; provided that R¹ is selected from isoxazolyl, pyrazolyl, thiazolyl or tetrahydropyridazinyl, where said is isoxazolyl, pyrazolyl, thiazolyl or tetrahydropyridazinyl is unsubstituted or substituted with one or more substituents independently selected from alkyl, haloalkyl, halogen, and hydroxyl when R² is a substituted or unsubstituted phenylalkyl group or provided that R¹ is selected from phenyl, pyrrolyl, pyrrolidinyl, isoxazolyl, pyrazolyl, thiazolyl, tetrahydrofuranyl, furanyl, thienyl or tetrahydropyridazinyl when R² is a substituted phenylalkyl group and said phenyl moiety of said substituted phenylalkyl group comprises one or more substituents other than halo or methyl, where said one or more substituents is independently selected from haloalkyl, amino, hydroxyl, alkoxy, haloalkoxy, alkylenedioxy, di-haloalkylenedioxy, cycloalkylalkyloxy, dialkylamino, alkylsulfonyl and alkylthio; or a prodrug, pharmaceutically active metabolite or pharmaceutically active salt or solvate thereof.
 25. The compound, according to any one of claims 20, 21 or 23, having the formula:

or a prodrug, pharmaceutically acceptable salt, pharmaceutically active metabolite, or pharmaceutically acceptable solvate thereof.
 26. The compound, according to any one of claims 20, 21 or 23, having the formula:

or a prodrug, pharmaceutically acceptable salt, pharmaceutically active metabolite, or pharmaceutically acceptable solvate thereof.
 27. The compound, according to any one of claims 20, 21 or 23, having the formula:

or a prodrug, pharmaceutically acceptable salt, pharmaceutically active metabolite, or pharmaceutically acceptable solvate thereof.
 28. A pharmaceutical composition comprising: a therapeutically effective amount of at least one HIV agent selected from compounds defined in any one of claims 20, 21 or 23; and a pharmaceutically acceptable carrier, diluent, vehicle, or excipient.
 29. The pharmaceutical composition according to claim 28 wherein the composition further comprises a therapeutically effective amount of at least one HIV infection/AIDS treatment agent selected from the group consisting of HIV/AIDS antiviral agents, immunomodulators, and anti-infective agents.
 30. The pharmaceutical composition according to claim 29, wherein the composition further comprises a therapeutically effective amount of at least one antiviral agent selected from the group consisting of non-nucleoside HIV reverse transcriptase inhibitors and nucleoside HIV reverse transcriptase inhibitors.
 31. The pharmaceutical composition according to claim 30, further comprising a therapeutically effective amount of at least one HIV protease inhibitor.
 32. A method of treating a mammalian disease condition mediated by HIV protease activity, comprising administering to a mammal in need thereof a therapeutically effective amount of at least one compound defined in any one of claims 20, 21 or
 23. 33. A method of inhibiting the activity of HIV protease in a subject in need thereof, comprising contacting the HIV protease with an effective amount of at least one compound defined in any one of claims 20, 21 or
 23. 34. A method of preventing or treating infection by HIV in a subject in need thereof comprising administering to the subject a therapeutically effective amount of a compound according to any one of claims 20, 21 or
 23. 35. The method according to claim 34, wherein the compound is administered in combination with a therapeutically effective amount of at least one HIV infection/AIDS treatment agent selected from the group consisting of HIV/AIDS antiviral agents, immunomodulators, and anti-infective agents.
 36. A compound selected from

and the prodrugs, pharmaceutically active metabolites, and pharmaceutically acceptable salts and solvates thereof. 